Catalyzes the specific attachment of an amino acid to its cognate tRNA in a 2 step reaction: the amino acid (AA) is first activated by ATP to form AA-AMP and then transferred to the acceptor end of the tRNA

Cytoplasm, cytosol

Hypomyelination with brainstem and spinal cord involvement and leg spasticity

An autosomal recessive leukoencephalopathy characterized by onset in the first year of life of severe spasticity, mainly affecting the lower limbs and resulting in an inability to achieve independent ambulation. Affected individuals show delayed motor development and nystagmus; some may have mild intellectual disability. Brain MRI shows hypomyelination and white matter lesions in the cerebrum, brainstem, cerebellum, and spinal cord.

SynapseCell membrane

Spinocerebellar ataxia 21

A form of spinocerebellar ataxia, a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCA21 is characterized by onset in the first decades of life of slowly progressive relatively mild cerebellar ataxia associated with slight extrapyramidal features predominant in older patients and cognitive impairment predominant in younger patients.

Catalyzes the NADPH-dependent reduction of trans-2-enoyl thioesters in mitochondrial fatty acid synthesis (fatty acid synthesis type II). Fatty acid chain elongation in mitochondria uses acyl carrier protein (ACP) as an acyl group carrier, but the enzyme accepts both ACP and CoA thioesters as substrates in vitro. Displays a preference for medium-chain over short- and long-chain substrates (PubMed:12654921, PubMed:18479707, PubMed:27817865). May provide the octanoyl chain used for lipoic acid bio

MitochondrionCytoplasmNucleus

Dystonia, childhood-onset, with optic atrophy and basal ganglia abnormalities

An autosomal recessive neurologic disorder characterized by childhood-onset dystonia, basal ganglia degeneration and optic atrophy with decreased visual acuity. Dystonia is defined by the presence of sustained involuntary muscle contraction, often leading to abnormal postures. DYTOABG severity is variable, and some patients lose independent ambulation.

In neurons, involved in the transport of late endosomes/lysosomes (PubMed:25066864). May be involved in dendrite morphogenesis and maintenance by regulating lysosomal trafficking (PubMed:25066864). May act as a molecular brake for retrograde transport of late endosomes/lysosomes, possibly via its interaction with MAP6 (By similarity). In motoneurons, may mediate the axonal transport of lysosomes and axonal sorting at the initial segment (By similarity). It remains unclear whether TMEM106B affect

Late endosome membraneLysosome membraneCell membrane

Frontotemporal dementia 2

A form of dementia characterized by pathologic finding of frontotemporal lobar degeneration, presenile dementia with behavioral changes, deterioration of cognitive capacities and loss of memory. Gestural apraxia, parkinsonism, visual loss, and visual hallucinations are present in 25 to 40% of patients.

Transcriptional corepressor. Recruits NR2E1 to repress transcription. Promotes vascular smooth cell (VSMC) migration and orientation (By similarity). Corepressor of MTG8 transcriptional repression. Has some intrinsic repression activity which is independent of the number of poly-Gln (polyQ) repeats

NucleusCytoplasm, perinuclear regionCell junction

Dentatorubral-pallidoluysian atrophy

Autosomal dominant neurodegenerative disorder characterized by a loss of neurons in the dentate nucleus, rubrum, glogus pallidus and Luys'body. Clinical features are myoclonus epilepsy, dementia, and cerebellar ataxia. Onset of the disease occurs usually in the second decade of life and death in the fourth.

Core subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) which catalyzes electron transfer from NADH through the respiratory chain, using ubiquinone as an electron acceptor (PubMed:16996290). Essential for the catalytic activity and assembly of complex I (PubMed:16996290)

Mitochondrion inner membrane

Leber hereditary optic neuropathy

A maternally inherited form of Leber hereditary optic neuropathy, a mitochondrial disease resulting in bilateral painless loss of central vision due to selective degeneration of the retinal ganglion cells and their axons. The disorder shows incomplete penetrance and male predominance. Cardiac conduction defects and neurological defects have also been described in some LHON patients. LHON results from primary mitochondrial DNA mutations affecting the respiratory chain complexes.

Deubiquitinating enzyme involved in protein homeostasis maintenance, transcription, cytoskeleton regulation, myogenesis and degradation of misfolded chaperone substrates (PubMed:12297501, PubMed:16118278, PubMed:17696782, PubMed:23625928, PubMed:28445460, PubMed:33157014). Binds long polyubiquitin chains and trims them, while it has weak or no activity against chains of 4 or less ubiquitins (PubMed:17696782). Involved in degradation of misfolded chaperone substrates via its interaction with STUB

Nucleus matrixNucleusLysosome membrane

Spinocerebellar ataxia 3

Spinocerebellar ataxia is a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to cerebellum degeneration with variable involvement of the brainstem and spinal cord. SCA3 belongs to the autosomal dominant cerebellar ataxias type I (ADCA I) which are characterized by cerebellar ataxia in combination with additional clinical features like optic atrophy, ophthalmoplegia, bulbar and extrapyramidal signs, peripheral neuropathy and dementia. The molecular defect in SCA3 is the a CAG repeat expansion in ATX3 coding region. Longer expansions result in earlier onset and more severe clinical manifestations of the disease.

May be involved in endosome fusion. Mediates down-regulation of growth factor signaling via internalization of growth factor receptors

Early endosomeMitochondrion

Ataxia-pancytopenia syndrome

An autosomal dominant disorder characterized by cerebellar ataxia, variable hematologic cytopenias, and predisposition to bone marrow failure and myeloid leukemia.

Plays a role in DNA damage repair as component of the ASCC complex (PubMed:29997253). Part of the ASC-1 complex that enhances NF-kappa-B, SRF and AP1 transactivation (PubMed:12077347). In cells responding to gastrin-activated paracrine signals, it is involved in the induction of SERPINB2 expression by gastrin. May also play a role in the development of neuromuscular junction

NucleusNucleus speckle

Barrett esophagus

A condition characterized by a metaplastic change in which normal esophageal squamous epithelium is replaced by a columnar and intestinal-type epithelium. Patients with Barrett esophagus have an increased risk of esophageal adenocarcinoma. The main cause of Barrett esophagus is gastroesophageal reflux. The retrograde movement of acid and bile salts from the stomach into the esophagus causes prolonged injury to the esophageal epithelium and induces chronic esophagitis, which in turn is believed to trigger the pathologic changes.

Subunit a, of the mitochondrial membrane ATP synthase complex (F(1)F(0) ATP synthase or Complex V) that produces ATP from ADP in the presence of a proton gradient across the membrane which is generated by electron transport complexes of the respiratory chain (Probable). ATP synthase complex consist of a soluble F(1) head domain - the catalytic core - and a membrane F(1) domain - the membrane proton channel (PubMed:37244256). These two domains are linked by a central stalk rotating inside the F(1

Mitochondrion inner membrane

Neuropathy, ataxia, and retinitis pigmentosa

A syndrome characterized by variable combination of developmental delay, psychomotor retardation, hearing loss, optic atrophy and retinitis pigmentosa, dementia, seizures, ataxia, proximal neurogenic muscle weakness, and sensory neuropathy.

Required for activation of guanine nucleotide-binding proteins (G-proteins) during non-canonical Wnt signaling (PubMed:26126266). Binds to ligand-activated Wnt receptor FZD7, displacing DVL1 from the FZD7 receptor and leading to inhibition of canonical Wnt signaling (PubMed:26126266). Acts as a non-receptor guanine nucleotide exchange factor by also binding to guanine nucleotide-binding protein G(i) alpha (Gi-alpha) subunits, leading to their activation (PubMed:26126266). Binding to Gi-alpha sub

CytoplasmCell junction

Hydrocephalus, congenital, 1

A form of congenital hydrocephalus, a disease characterized by onset in utero of enlarged ventricles due to accumulation of ventricular cerebrospinal fluid. Affected individuals may have neurologic impairment. HYC1 inheritance is autosomal recessive.

Catalyzes the deacetylation of N-acetylaspartic acid (NAA) to produce acetate and L-aspartate. NAA occurs in high concentration in brain and its hydrolysis NAA plays a significant part in the maintenance of intact white matter. In other tissues it acts as a scavenger of NAA from body fluids

CytoplasmNucleus

Canavan disease

A rare neurodegenerative condition of infancy or childhood characterized by white matter vacuolization and demyelination that gives rise to a spongy appearance. The clinical features are onset in early infancy, atonia of neck muscles, hypotonia, hyperextension of legs and flexion of arms, blindness, severe mental defect, megalocephaly, and death by 18 months on the average.

Plays a regulatory role in the processing of the amyloid-beta A4 precursor protein (APP) and acts as an inhibitor of the amyloid-beta peptide aggregation and fibrils deposition. Plays a role in the induction of neurite outgrowth. Functions as a protease inhibitor by blocking access of secretases to APP cleavage sites Mature BRI2 (mBRI2) functions as a modulator of the amyloid-beta A4 precursor protein (APP) processing leading to a strong reduction in the secretion of secretase-processed amyloid-

Golgi apparatus membraneCell membraneEndosome membraneSecreted

Cerebral amyloid angiopathy, ITM2B-related 1

A disorder characterized by amyloid deposition in the walls of cerebral blood vessels and neurodegeneration in the central nervous system. Cerebral amyloid angiopathy, non-neuritic and perivascular plaques and neurofibrillary tangles are the predominant pathological lesions. Clinical features include progressive mental deterioration, spasticity and muscular rigidity.

May be involved in vesicular trafficking from the Golgi apparatus to the cell membrane. Plays a role in the maintenance of the myelin sheath, and in axon-glia and glia-glia interactions

MembraneCell membrane

Leukodystrophy, hypomyelinating, 28

A form of hypomyelinating leukodystrophy, a group of heterogeneous disorders characterized by persistent deficit of myelin observed on brain imaging. HLD28 is an autosomal recessive form characterized by developmental delay and nystagmus in infancy, followed by significant learning disabilities and progressive motor deterioration within the first decade.

This is the major myelin protein from the central nervous system. It plays an important role in the formation or maintenance of the multilamellar structure of myelin

Cell membraneMyelin membrane

Leukodystrophy, hypomyelinating, 1

An X-linked recessive disorder of the central nervous system in which myelin is not formed properly. Clinically characterized by nystagmus, spastic quadriplegia, ataxia, and developmental delay.

The SMN complex catalyzes the assembly of small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome, and thereby plays an important role in the splicing of cellular pre-mRNAs (PubMed:18984161, PubMed:9845364). Most spliceosomal snRNPs contain a common set of Sm proteins SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF and SNRPG that assemble in a heptameric protein ring on the Sm site of the small nuclear RNA to form the core snRNP (Sm core) (PubMed:18984161). In the cytosol,

Nucleus, gemNucleus, Cajal bodyCytoplasmCytoplasmic granulePerikaryonCell projection, neuron projectionCell projection, axonCytoplasm, myofibril, sarcomere, Z line

Spinal muscular atrophy 1

A form of spinal muscular atrophy, a group of neuromuscular disorder characterized by degeneration of the anterior horn cells of the spinal cord, leading to symmetrical muscle weakness and atrophy. Autosomal recessive forms are classified according to the age of onset, the maximum muscular activity achieved, and survivorship. The severity of the disease is mainly determined by the copy number of SMN2, a copy gene which predominantly produces exon 7-skipped transcripts and only low amount of full-length transcripts that encode for a protein identical to SMN1. Only about 4% of SMA patients bear one SMN1 copy with an intragenic mutation. SMA1 is a severe form, with onset before 6 months of age. SMA1 patients never achieve the ability to sit.

Negatively regulates signaling through the G-protein coupled thromboxane A2 receptor (TBXA2R) (PubMed:19464661). May be involved in mechanisms like programmed cell death, craniofacial development, patterning of the limbs, and formation of the left-right axis (By similarity). Involved in the organization of apical junctions; the function is proposed to implicate a NPHP1-4-8 module. Does not seem to be strictly required for ciliogenesis (PubMed:19464661). Involved in establishment of planar cell p

CytoplasmCytoplasm, cytoskeleton, cilium basal bodyCytoplasm, cytoskeleton, cilium axonemeCytoplasm, cytoskeleton, microtubule organizing center, centrosomeCell junction, tight junction

G-protein coupled receptor for glutamate. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors. Signaling activates a phosphatidylinositol-calcium second messenger system. May participate in the central action of glutamate in the CNS, such as long-term potentiation in the hippocampus and long-term depression in the cerebellum (PubMed:24603153, PubMed:28886343, PubMed:7476890).

Cell membranePostsynaptic cell membraneCell projection, dendrite

Spinocerebellar ataxia, autosomal recessive, 13

A form of spinocerebellar ataxia, a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCAR13 is characterized by delayed psychomotor development beginning in infancy. Affected individuals show mild to profound intellectual disability with poor or absent speech as well as gait and stance ataxia and hyperreflexia.

Component of the U7 snRNP complex that is involved in the histone 3'-end pre-mRNA processing (PubMed:11574479, PubMed:16914750, PubMed:33230297). Increases U7 snRNA levels but not histone 3'-end pre-mRNA processing activity, when overexpressed (PubMed:11574479, PubMed:16914750). Required for cell cycle progression from G1 to S phases (By similarity). Binds specifically to the Sm-binding site of U7 snRNA (PubMed:11574479, PubMed:16914750)

Nucleus

Aicardi-Goutieres syndrome 8

A form of Aicardi-Goutieres syndrome, a genetically heterogeneous disease characterized by cerebral atrophy, leukoencephalopathy, intracranial calcifications, chronic cerebrospinal fluid (CSF) lymphocytosis, increased CSF alpha-interferon, and negative serologic investigations for common prenatal infection. Clinical features as thrombocytopenia, hepatosplenomegaly and elevated hepatic transaminases along with intermittent fever may erroneously suggest an infective process. Severe neurological dysfunctions manifest in infancy as progressive microcephaly, spasticity, dystonic posturing and profound psychomotor retardation. Death often occurs in early childhood. AGS8 inheritance is autosomal recessive.

Major cellular 3'-to-5' DNA exonuclease which digests single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) with mismatched 3' termini (PubMed:10391904, PubMed:10393201, PubMed:17293595). Prevents cell-intrinsic initiation of autoimmunity (PubMed:10391904, PubMed:10393201, PubMed:17293595). Acts by metabolizing DNA fragments from endogenous retroelements, including L1, LTR and SINE elements (PubMed:10391904, PubMed:10393201, PubMed:17293595). Plays a key role in degradation of DNA fragment

NucleusCytoplasm, cytosolEndoplasmic reticulum membrane

Aicardi-Goutieres syndrome 1

A form of Aicardi-Goutieres syndrome, a genetically heterogeneous disease characterized by cerebral atrophy, leukoencephalopathy, intracranial calcifications, chronic cerebrospinal fluid (CSF) lymphocytosis, increased CSF alpha-interferon, and negative serologic investigations for common prenatal infection. Clinical features as thrombocytopenia, hepatosplenomegaly and elevated hepatic transaminases along with intermittent fever may erroneously suggest an infective process. Severe neurological dysfunctions manifest in infancy as progressive microcephaly, spasticity, dystonic posturing and profound psychomotor retardation. Death often occurs in early childhood.

Non catalytic subunit of RNase H2, an endonuclease that specifically degrades the RNA of RNA:DNA hybrids. Participates in DNA replication, possibly by mediating the removal of lagging-strand Okazaki fragment RNA primers during DNA replication. Mediates the excision of single ribonucleotides from DNA:RNA duplexes

Nucleus

Aicardi-Goutieres syndrome 3

A form of Aicardi-Goutieres syndrome, a genetically heterogeneous disease characterized by cerebral atrophy, leukoencephalopathy, intracranial calcifications, chronic cerebrospinal fluid (CSF) lymphocytosis, increased CSF alpha-interferon, and negative serologic investigations for common prenatal infection. Clinical features as thrombocytopenia, hepatosplenomegaly and elevated hepatic transaminases along with intermittent fever may erroneously suggest an infective process. Severe neurological dysfunctions manifest in infancy as progressive microcephaly, spasticity, dystonic posturing and profound psychomotor retardation. Death often occurs in early childhood.

Positively regulates SLC1A1/EAAC1-mediated glutamate transport by increasing its affinity for glutamate in a PKC activity-dependent manner. Promotes the catalytic efficiency of SLC1A1/EAAC1 probably by reducing its interaction with ARL6IP5, a negative regulator of SLC1A1/EAAC1-mediated glutamate transport (By similarity). Plays a role in the formation and stabilization of endoplasmic reticulum tubules (PubMed:24262037). Negatively regulates apoptosis, possibly by modulating the activity of caspa

Endomembrane systemEndoplasmic reticulum membraneEndoplasmic reticulum

Spastic paraplegia 61, autosomal recessive

A complicated form of spastic paraplegia with polysensory and motor neuropathy. Spastic paraplegia is a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body.

Component of the ERLIN1/ERLIN2 complex which mediates the endoplasmic reticulum-associated degradation (ERAD) of inositol 1,4,5-trisphosphate receptors (IP3Rs). Involved in regulation of cellular cholesterol homeostasis by regulation the SREBP signaling pathway (PubMed:37683630). Binds cholesterol and may promote ER retention of the SCAP-SREBF complex (PubMed:24217618) (Microbial infection) Required early in hepatitis C virus (HCV) infection to initiate RNA replication, and later in the infectio

Endoplasmic reticulum membrane

Spastic paraplegia 62, autosomal recessive

A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body.

Functions as an activator of persulfide transfer to the scaffoding protein ISCU as component of the core iron-sulfur cluster (ISC) assembly complex and participates to the [2Fe-2S] cluster assembly (PubMed:12785837, PubMed:24971490). Accelerates sulfur transfer from NFS1 persulfide intermediate to ISCU and to small thiols such as L-cysteine and glutathione leading to persulfuration of these thiols and ultimately sulfide release (PubMed:24971490). Binds ferrous ion and is released from FXN upon t

MitochondrionCytoplasm, cytosol

Friedreich ataxia

Autosomal recessive, progressive degenerative disease characterized by neurodegeneration and cardiomyopathy it is the most common inherited ataxia. The disorder is usually manifest before adolescence and is generally characterized by incoordination of limb movements, dysarthria, nystagmus, diminished or absent tendon reflexes, Babinski sign, impairment of position and vibratory senses, scoliosis, pes cavus, and hammer toe. In most patients, FRDA is due to GAA triplet repeat expansions in the first intron of the frataxin gene. But in some cases the disease is due to mutations in the coding region.

Palmitoyl thioesterase specifically expressed in the endoplasmic reticulum of neurons. Modulates the trafficking of the glutamate receptor, AMPAR, to plasma membrane through depalmitoylation of GRIA1 (PubMed:30135643). Also regulates AMPR trafficking through the regulation of SACM1L phosphatidylinositol-3-phosphatase activity by interaction in a malonyl-CoA dependent manner (By similarity). Binds malonyl-CoA and couples malonyl-CoA to ceramide levels, necessary for proper spine maturation and co

Cell projection, dendriteCell projection, axonEndoplasmic reticulum membrane

Spastic paraplegia 73, autosomal dominant

A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body.

Lipophagy receptor that plays an important role in lipid droplet (LD) turnover in motor neurons (PubMed:37443287). Localizes to LDs and interacts with components of the autophagy machinery, such as MAP1LC3A/C proteins to deliver LDs to autophagosomes for degradation via lipophagy (PubMed:37443287). Lipid transfer protein required for lipid droplet degradation, including by lipophagy (PubMed:38190532). Can bind and transfer all lipid species found in lipid droplets, from phospholipids to triglyce

CytoplasmMidbodyLipid droplet

Spastic paraplegia 20, autosomal recessive

A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. SPG20 is characterized by dysarthria, distal amyotrophy, mild developmental delay and short stature.

Catalyzes the transport of triglyceride, cholesteryl ester, and phospholipid between phospholipid surfaces (PubMed:15897609, PubMed:16478722, PubMed:22236406, PubMed:23475612, PubMed:25108285, PubMed:26224785, PubMed:8876250, PubMed:8939939). Required for the assembly and secretion of plasma lipoproteins that contain apolipoprotein B (PubMed:16478722, PubMed:23475612, PubMed:26224785, PubMed:8876250, PubMed:8939939). May be involved in regulating cholesteryl ester biosynthesis in cells that prod

Endoplasmic reticulumGolgi apparatus

Abetalipoproteinemia

An autosomal recessive disorder of lipoprotein metabolism. Affected individuals produce virtually no circulating apolipoprotein B-containing lipoproteins (chylomicrons, VLDL, LDL, lipoprotein(A)). Malabsorption of the antioxidant vitamin E occurs, leading to spinocerebellar and retinal degeneration.

Acts as a positive regulator of ERK phosphorylation downstream of fibroblast growth factor-receptor activation (PubMed:23862974, PubMed:28157540). Involved in the regulation of both caspase-dependent apoptosis and caspase-independent cell death (PubMed:15178406). In the skin, it plays a predominant role in suppressing caspase-dependent apoptosis in response to UV stress in a range of dermal cell types (PubMed:28157540)

CytoplasmCell membraneApical cell membraneBasolateral cell membraneCell junction

Congenital anomalies of the kidney and urinary tract 1

A disorder encompassing a broad spectrum of renal and urinary tract malformations that include renal agenesis, kidney hypodysplasia, multicystic kidney dysplasia, duplex collecting system, posterior urethral valves and ureter abnormalities. Congenital anomalies of kidney and urinary tract are the commonest cause of chronic kidney disease in children.

Catalytic core component of RNA polymerase III (Pol III), a DNA-dependent RNA polymerase which synthesizes small non-coding RNAs using the four ribonucleoside triphosphates as substrates. Synthesizes 5S rRNA, snRNAs, tRNAs and miRNAs from at least 500 distinct genomic loci (PubMed:19609254, PubMed:19631370, PubMed:20413673, PubMed:33335104, PubMed:33558764, PubMed:33558766, PubMed:34675218, PubMed:35637192, PubMed:9331371). Pol III-mediated transcription cycle proceeds through transcription init

NucleusCytoplasm, cytosol

Leukodystrophy, hypomyelinating, 7, with or without oligodontia and/or hypogonadotropic hypogonadism

An autosomal recessive neurodegenerative disorder characterized by childhood onset of progressive motor decline manifest as spasticity, ataxia, tremor, and cerebellar signs, as well as mild cognitive regression. Other features may include hypodontia or oligodontia and hypogonadotropic hypogonadism. There is considerable inter- and intrafamilial variability.

Non-catalytic component of the RNA exosome complex which has 3'->5' exoribonuclease activity and participates in a multitude of cellular RNA processing and degradation events. In the nucleus, the RNA exosome complex is involved in proper maturation of stable RNA species such as rRNA, snRNA and snoRNA, in the elimination of RNA processing by-products and non-coding 'pervasive' transcripts, such as antisense RNA species and promoter-upstream transcripts (PROMPTs), and of mRNAs with processing defe

CytoplasmNucleusNucleus, nucleolusNucleus, nucleoplasm

Pontocerebellar hypoplasia 1D

An autosomal recessive neurologic disorder with onset at birth or in infancy, and characterized by progressive axonal motor neuronopathy, severe generalized hypotonia, respiratory insufficiency, and cerebellar atrophy. Death in childhood may occur.

Anti-apoptotic protein which acts by inhibiting the activities of CASP3, CASP7 and CASP9. Can inhibit the autocleavage of pro-CASP9 and cleavage of pro-CASP3 by CASP9. Capable of inhibiting CASP9 autoproteolysis at 'Asp-315' and decreasing the rate of auto proteolysis at 'Asp-330'. Acts as a mediator of neuronal survival in pathological conditions. Prevents motor-neuron apoptosis induced by a variety of signals. Possible role in the prevention of spinal muscular atrophy that seems to be caused b

Catalyzes the GTP-dependent ribosomal translocation step during translation elongation (PubMed:26593721). During this step, the ribosome changes from the pre-translocational (PRE) to the post-translocational (POST) state as the newly formed A-site-bound peptidyl-tRNA and P-site-bound deacylated tRNA move to the P and E sites, respectively (PubMed:26593721). Catalyzes the coordinated movement of the two tRNA molecules, the mRNA and conformational changes in the ribosome (PubMed:26593721)

CytoplasmNucleus

Spinocerebellar ataxia 26

A form of spinocerebellar ataxia, a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord.

Ribonuclease that plays an essential role in innate immune response by recognizing and degrading RNAs from microbial pathogens that are subsequently sensed by TLR8 (PubMed:31778653). Cleaves preferentially single-stranded RNA molecules between purine and uridine residues, which critically contributes to the supply of catabolic uridine and the generation of purine-2',3'-cyclophosphate-terminated oligoribonucleotides (PubMed:31778653, PubMed:38697119). In turn, RNase T2 degradation products promot

SecretedLysosome lumenEndoplasmic reticulum lumenMitochondrion intermembrane space

Leukoencephalopathy, cystic, without megalencephaly

An infantile-onset syndrome of cerebral leukoencephalopathy. Affected newborns develop microcephaly and neurologic abnormalities including psychomotor impairment, seizures and sensorineural hearing impairment. The brain shows multifocal white matter lesions, anterior temporal lobe subcortical cysts, pericystic abnormal myelination, ventriculomegaly and intracranial calcifications.

Catalyzes the reversible transamination between alanine and 2-oxoglutarate to form pyruvate and glutamate

Neurodevelopmental disorder with spastic paraplegia and microcephaly

An autosomal recessive syndrome characterized by severe psychomotor developmental delay, dysarthria, walking difficulties, moderately to severely impaired intellectual development, poor or absent speech, and progressive microcephaly.

GFAP, a class-III intermediate filament, is a cell-specific marker that, during the development of the central nervous system, distinguishes astrocytes from other glial cells

Cytoplasm

Alexander disease

A rare disorder of the central nervous system. The most common form affects infants and young children, and is characterized by progressive failure of central myelination, usually leading to death within the first decade. Infants with Alexander disease develop a leukodystrophy with macrocephaly, seizures, and psychomotor retardation. Patients with juvenile or adult forms typically experience ataxia, bulbar signs and spasticity, and a more slowly progressive course. Histologically, Alexander disease is characterized by Rosenthal fibers, homogeneous eosinophilic inclusions in astrocytes.

ATP-dependent 5'->3' DNA/RNA helicase that preferentially unwinds RNA substrates over DNA, playing a crucial role in resolving R-loops and promoting transcription termination (PubMed:36864660). Plays a role in transcription regulation by its ability to modulate RNA Polymerase II (Pol II) binding to chromatin and through its interaction with proteins involved in transcription (PubMed:19515850, PubMed:21700224). Contributes to the mRNA splicing efficiency and splice site selection (PubMed:19515850

NucleusNucleus, nucleoplasmNucleus, nucleolusCytoplasmChromosomeChromosome, telomereCell projection, axonCell projection, growth cone

Spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 2

A form of spinocerebellar ataxia, a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCAN2 is an autosomal recessive form associated with peripheral neuropathy and elevated serum alpha-fetoprotein, immunoglobulins and, less commonly, creatine kinase levels. Some SCAN2 patients manifest oculomotor apraxia.

Serine/threonine kinase involved in the regulation of key cellular processes including the cell cycle, nuclear condensation, transcription regulation, and DNA damage response (PubMed:14645249, PubMed:18617507, PubMed:19103756, PubMed:33076429). Controls chromatin organization and remodeling by mediating phosphorylation of histone H3 on 'Thr-4' and histone H2AX (H2aXT4ph) (PubMed:31527692, PubMed:37179361). It also phosphorylates KAT5 in response to DNA damage, promoting KAT5 association with chr

NucleusCytoplasmNucleus, Cajal body

Pontocerebellar hypoplasia 1A

A form of pontocerebellar hypoplasia, a disorder characterized by structural defects of the pons and cerebellum, evident upon brain imaging. PCH1A is an autosomal recessive form characterized by an abnormally small cerebellum and brainstem, central and peripheral motor dysfunction from birth, gliosis and spinal cord anterior horn cells degeneration resembling infantile spinal muscular atrophy. Additional features include muscle hypotonia, congenital contractures and respiratory insufficiency that is evident at birth.

Non-catalytic component of the RNA exosome complex which has 3'->5' exoribonuclease activity and participates in a multitude of cellular RNA processing and degradation events. In the nucleus, the RNA exosome complex is involved in proper maturation of stable RNA species such as rRNA, snRNA and snoRNA, in the elimination of RNA processing by-products and non-coding 'pervasive' transcripts, such as antisense RNA species and promoter-upstream transcripts (PROMPTs), and of mRNAs with processing defe

CytoplasmNucleus, nucleolusNucleus

Pontocerebellar hypoplasia 1B

A severe autosomal recessive neurologic disorder characterized by a combination of cerebellar and spinal motor neuron degeneration beginning at birth. There is diffuse muscle weakness, progressive microcephaly, global developmental delay, and brainstem involvement.

Non-catalytic component of the RNA exosome complex which has 3'->5' exoribonuclease activity and participates in a multitude of cellular RNA processing and degradation events. In the nucleus, the RNA exosome complex is involved in proper maturation of stable RNA species such as rRNA, snRNA and snoRNA, in the elimination of RNA processing by-products and non-coding 'pervasive' transcripts, such as antisense RNA species and promoter-upstream transcripts (PROMPTs), and of mRNAs with processing defe

CytoplasmNucleusNucleus, nucleolus

Pontocerebellar hypoplasia 1C

A severe autosomal recessive neurodegenerative disease characterized by cerebellar and corpus callosum hypoplasia, abnormal myelination of the central nervous system, and spinal motor neuron disease. Affected individuals manifest failure to thrive, severe muscle weakness, spasticity and psychomotor retardation. Vision and hearing are impaired.

Signaling adapter of the reelin-mediated signaling pathway, which regulates the migration and differentiation of postmitotic neurons during brain development. Mediates intracellular transduction of Reelin signaling following reelin (RELN)-binding to its receptor: acts by docking proteins through its phosphotyrosine residues and PID domain

Cytoplasm

Spinocerebellar ataxia 37

A form of spinocerebellar ataxia, a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCA37 is an autosomal dominant form characterized by adult-onset of slowly progressive gait instability, frequent falls, and dysarthria associated with cerebellar atrophy on brain imaging.

Multifunctional cell surface receptor that binds VLDL and transports it into cells by endocytosis and therefore plays an important role in energy metabolism. Also binds to a wide range of other molecules including Reelin/RELN or apolipoprotein E/APOE-containing ligands as well as clusterin/CLU (PubMed:24381170, PubMed:30873003). In the off-state of the pathway, forms homooligomers or heterooligomers with LRP8 (PubMed:30873003). Upon binding to ligands, homooligomers are rearranged to higher orde

Cell membraneMembrane, clathrin-coated pit

Cerebellar ataxia, impaired intellectual development, and dysequilibrium syndrome 1

An autosomal recessive, congenital, non-progressive cerebellar ataxia associated with disturbed equilibrium, delayed ambulation, intellectual disability, cerebellar hypoplasia and mild cerebral gyral simplification. Additional features include short stature, strabismus, pes planus and, rarely, seizures.

May act as a GTPase regulator. Controls survival and growth of spinal motoneurons (By similarity)

Amyotrophic lateral sclerosis 2

A neurodegenerative disorder affecting upper motor neurons in the brain and lower motor neurons in the brain stem and spinal cord, resulting in fatal paralysis. Sensory abnormalities are absent. The pathologic hallmarks of the disease include pallor of the corticospinal tract due to loss of motor neurons, presence of ubiquitin-positive inclusions within surviving motor neurons, and deposition of pathologic aggregates. The etiology of amyotrophic lateral sclerosis is likely to be multifactorial, involving both genetic and environmental factors. The disease is inherited in 5-10% of the cases.

Bifunctional enzyme that converts glutamate to glutamate 5-semialdehyde, an intermediate in the biosynthesis of proline, ornithine and arginine

MitochondrionMitochondrion matrix

Cutis laxa, autosomal recessive, 3A

A syndrome characterized by facial dysmorphism with a progeroid appearance, large and late-closing fontanel, cutis laxa, joint hyperlaxity, athetoid movements and hyperreflexia, pre- and postnatal growth retardation, intellectual deficit, developmental delay, and ophthalmologic abnormalities.

The large binding pocket can accommodate several single chain phospholipids and fatty acids, GM2A also exhibits some calcium-independent phospholipase activity (By similarity). Binds gangliosides and stimulates ganglioside GM2 degradation. It stimulates only the breakdown of ganglioside GM2 and glycolipid GA2 by beta-hexosaminidase A. It extracts single GM2 molecules from membranes and presents them in soluble form to beta-hexosaminidase A for cleavage of N-acetyl-D-galactosamine and conversion

Lysosome

GM2-gangliosidosis AB

An autosomal recessive lysosomal storage disease marked by the accumulation of GM2 gangliosides in the neuronal cells. It is characterized by GM2 gangliosides accumulation in the presence of both normal hexosaminidase A and B.

Electroneutral Na(+) /H(+) antiporter that extrudes Na(+) in exchange for external protons driven by the inward sodium ion chemical gradient, protecting cells from acidification that occurs from metabolism (PubMed:11350981, PubMed:11532004, PubMed:14680478, PubMed:15035633, PubMed:15677483, PubMed:17073455, PubMed:17493937, PubMed:22020933, PubMed:27650500, PubMed:32130622, PubMed:7110335, PubMed:7603840). Exchanges intracellular H(+) ions for extracellular Na(+) in 1:1 stoichiometry (By similar

Cell membraneBasolateral cell membrane

Lichtenstein-Knorr syndrome

An autosomal recessive neurologic disorder characterized by progressive cerebellar ataxia and severe progressive sensorineural hearing loss.

Component of the ESCRT-I complex, a regulator of vesicular trafficking process (PubMed:21757351, PubMed:22405001, PubMed:31203368). Binds to ubiquitinated cargo proteins and is required for the sorting of endocytic ubiquitinated cargos into multivesicular bodies (MVBs) (PubMed:21757351, PubMed:22405001). Plays a role in the proteasomal degradation of ubiquitinated cell-surface proteins, such as EGFR and BST2 (PubMed:22405001, PubMed:24284069, PubMed:31203368)

Cytoplasm, cytosolEndosome

Spastic paraplegia 80, autosomal dominant

A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body.

Probably plays a role as positive regulator of autophagy

Neuropathy, hereditary sensory and autonomic, 9, with developmental delay

A form of hereditary sensory and autonomic neuropathy, a genetically and clinically heterogeneous group of disorders characterized by degeneration of dorsal root and autonomic ganglion cells, and by sensory and/or autonomic abnormalities. HSAN9 is characterized by global developmental delay and intellectual disability, axial and appendicular hypotonia, dysarthria, and an abnormal gait that is often described as ataxic. Other features may include peripheral neuropathy, hyporeflexia, and autonomic dysfunction. Affected individuals also have dysmorphic features, thin corpus callosum on brain imaging, and episodes of central apnea, which may be fatal.

5' to 3' helicase that unwinds RNA and DNA duplexes in an ATP-dependent reaction (PubMed:19158098, PubMed:22999958, PubMed:30218034). Specific to 5'-phosphorylated single-stranded guanine-rich sequences (PubMed:22999958, PubMed:8349627). May play a role in RNA metabolism, ribosome biogenesis or initiation of translation (PubMed:19158098, PubMed:19299493). May play a role in regulation of transcription (By similarity). Interacts with tRNA-Tyr (PubMed:19299493)

NucleusCytoplasmCell projection, axon

Neuronopathy, distal hereditary motor, autosomal recessive 1

A form of distal hereditary motor neuronopathy, a heterogeneous group of neuromuscular disorders caused by selective degeneration of motor neurons in the anterior horn of the spinal cord, without sensory deficit in the posterior horn. The overall clinical picture consists of a classical distal muscular atrophy syndrome in the legs without clinical sensory loss. The disease starts with weakness and wasting of distal muscles of the anterior tibial and peroneal compartments of the legs. Later on, weakness and atrophy may expand to the proximal muscles of the lower limbs and/or to the distal upper limbs.

Catalyzes the attachment of tryptophan to tRNA(Trp) in a two-step reaction: tryptophan is first activated by ATP to form Trp-AMP and then transferred to the acceptor end of the tRNA(Trp) Has no angiostatic activity Possesses an angiostatic activity but has no aminoacylation activity (PubMed:11773625, PubMed:11773626, PubMed:14630953). Inhibits fluid shear stress-activated responses of endothelial cells (PubMed:14630953). Regulates ERK, Akt, and eNOS activation pathways that are associated with a

Cytoplasm

Neuronopathy, distal hereditary motor, autosomal dominant 9

A form of distal hereditary motor neuronopathy, a heterogeneous group of neuromuscular disorders caused by selective degeneration of motor neurons in the anterior horn of the spinal cord, without sensory deficit in the posterior horn. The overall clinical picture consists of a classical distal muscular atrophy syndrome in the legs without clinical sensory loss. The disease starts with weakness and wasting of distal muscles of the anterior tibial and peroneal compartments of the legs. Later on, weakness and atrophy may expand to the proximal muscles of the lower limbs and/or to the distal upper limbs. HMND9 is characterized by juvenile onset of slowly progressive distal muscle weakness and atrophy affecting both the lower and upper limbs.

Contributes to tetrahydrofolate metabolism. Helps regulate carbon flow through the folate-dependent one-carbon metabolic network that supplies carbon for the biosynthesis of purines, thymidine and amino acids. Catalyzes the irreversible conversion of 5-formyltetrahydrofolate (5-FTHF) to yield 5,10-methenyltetrahydrofolate

Cytoplasm

Neurodevelopmental disorder with microcephaly, epilepsy, and hypomyelination

An autosomal recessive neurodevelopmental disorder with onset at birth or in early infancy, and characterized by microcephaly, short stature, severe global developmental delay, progressive spasticity, and epilepsy. Brain imaging shows delayed myelination, hypomyelination, enlarged ventricles, and cerebellar atrophy.

Plays an important role in maintenance of mitochondrial morphology and in mediating either calcium or potassium/proton antiport (PubMed:18628306, PubMed:19797662, PubMed:24344246, PubMed:24898248, PubMed:29123128, PubMed:32139798, PubMed:36055214, PubMed:36321428). Mediates proton-dependent calcium efflux from mitochondrion (PubMed:19797662, PubMed:24344246, PubMed:29123128). Also functions as an electroneutral mitochondrial proton/potassium exchanger (PubMed:24898248, PubMed:36055214, PubMed:36

Mitochondrion inner membrane

Neurodegeneration, childhood-onset, with multisystem involvement due to mitochondrial dysfunction

An autosomal recessive disorder characterized primarily by global developmental delay and variably impaired intellectual development with speech delay apparent from infancy. Affected individuals have hypotonia, poor feeding, poor overall growth, and respiratory distress early in life. Other features include visual impairment due to optic atrophy, sensorineural hearing loss, and neuromuscular abnormalities. Features suggestive of a mitochondrial disorder include cataracts, cardiomyopathy, diabetes mellitus, combined oxidative phosphorylation deficiency, and increased lactate. Some patients develop seizures, some have dysmorphic facial features, and some have non-specific abnormalities on brain imaging. Death in childhood may occur.

Choline/H+ antiporter (PubMed:19357133, PubMed:23651124, PubMed:31855247, PubMed:33789160). Also acts as a high-affinity ethanolamine/H+ antiporter, regulating the supply of extracellular ethanolamine (Etn) for the CDP-Etn pathway, redistribute intracellular Etn and balance the CDP-Cho and CDP-Etn arms of the Kennedy pathway (PubMed:33789160). Involved in membrane synthesis and myelin production (PubMed:31855247)

Cell membraneMitochondrion outer membrane

Neurodegeneration, childhood-onset, with ataxia, tremor, optic atrophy, and cognitive decline

An autosomal recessive neurodegenerative disease characterized by progressive ataxia, tremor, cognitive decline, dysphagia, optic atrophy, dysarthria, as well as urinary and bowel incontinence. Brain MRI demonstrates cerebellar atrophy and leukoencephalopathy.

Stores iron in a soluble, non-toxic, readily available form. Important for iron homeostasis. Has ferroxidase activity (PubMed:9003196). Iron is taken up in the ferrous form and deposited as ferric hydroxides after oxidation (PubMed:9003196). Also plays a role in delivery of iron to cells (By similarity). Mediates iron uptake in capsule cells of the developing kidney (By similarity). Delivery to lysosomes is mediated by the cargo receptor NCOA4 for autophagic degradation and release of iron (PubM

CytoplasmLysosomeCytoplasmic vesicle, autophagosome

Hemochromatosis 5

A disorder of iron metabolism characterized by iron overload. Excess iron is deposited in a variety of organs leading to their failure, and resulting in serious illnesses including cirrhosis, hepatomas, diabetes, cardiomyopathy, arthritis, and hypogonadotropic hypogonadism. Severe effects of the disease usually do not appear until after decades of progressive iron loading.

Mitochondrial isoform that catalyzes the phosphorylation of pantothenate to generate 4'-phosphopantothenate in the first and rate-determining step of coenzyme A (CoA) synthesis (PubMed:15659606, PubMed:16272150, PubMed:17242360, PubMed:17825826). Required for angiogenic activity of umbilical vein of endothelial cells (HUVEC) (PubMed:30221726) Cytoplasmic isoform that catalyzes the phosphorylation of pantothenate to generate 4'-phosphopantothenate in the first and rate-determining step of coenzym

MitochondrionMitochondrion intermembrane spaceNucleusCytoplasm

Neurodegeneration with brain iron accumulation 1

Autosomal recessive neurodegenerative disorder associated with iron accumulation in the brain, primarily in the basal ganglia. Clinical manifestations include progressive muscle spasticity, hyperreflexia, muscle rigidity, dystonia, dysarthria, and intellectual deterioration which progresses to severe dementia over several years. It is clinically classified into classic, atypical, and intermediate phenotypes. Classic forms present with onset in first decade, rapid progression, loss of independent ambulation within 15 years. Atypical forms have onset in second decade, slow progression, maintenance of independent ambulation up to 40 years later. Intermediate forms manifest onset in first decade with slow progression or onset in second decade with rapid progression. Patients with early onset tend to also develop pigmentary retinopathy, whereas those with later onset tend to also have speech disorders and psychiatric features. All patients have the 'eye of the tiger' sign on brain MRI.

Uniporter that mediates the transport of copper(1+) from the extracellular space to the cytoplasm, across the plasma membrane (PubMed:11734551, PubMed:16135512, PubMed:17525160, PubMed:19740744, PubMed:20451502, PubMed:20569931, PubMed:23658018) and delivers directly copper(1+) to specific chaperone such as ATOX1, via a copper(1+)- mediated transient interaction between the C-terminal domain and a copper(1+) chaperone, thus controlling intracellular copper(1+) levels (PubMed:11734551, PubMed:161

Cell membraneEarly endosome membraneRecycling endosome membraneApical cell membraneLate endosome membraneBasolateral cell membrane

Neurodegeneration and seizures due to copper transport defect

An autosomal recessive disorder of copper metabolism characterized by global developmental delay, seizures, cortical and cerebellar atrophy, and axial hypotonia. Death in infancy may occur.

Mitochondrial helicase involved in mtDNA replication and repair (PubMed:12975372, PubMed:15167897, PubMed:17324440, PubMed:18039713, PubMed:18971204, PubMed:25824949, PubMed:26887820, PubMed:27226550). Might have a role in mtDNA repair (PubMed:27226550). Has DNA strand separation activity needed to form a processive replication fork for leading strand synthesis which is catalyzed by the formation of a replisome complex with POLG and mtSDB (PubMed:12975372, PubMed:15167897, PubMed:18039713, PubMe

Mitochondrion matrix, mitochondrion nucleoidMitochondrion inner membrane

Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant, 3

A disorder characterized by progressive weakness of ocular muscles and levator muscle of the upper eyelid. In a minority of cases, it is associated with skeletal myopathy, which predominantly involves axial or proximal muscles and which causes abnormal fatigability and even permanent muscle weakness. Ragged-red fibers and atrophy are found on muscle biopsy. A large proportion of chronic ophthalmoplegias are associated with other symptoms, leading to a multisystemic pattern of this disease. Additional symptoms are variable, and may include cataracts, hearing loss, sensory axonal neuropathy, ataxia, depression, hypogonadism, and parkinsonism.

Catalyzes the attachment of alanine to tRNA(Ala) in a two-step reaction: alanine is first activated by ATP to form Ala-AMP and then transferred to the acceptor end of tRNA(Ala). Also edits incorrectly charged tRNA(Ala) via its editing domain (PubMed:21549344). In presence of high levels of lactate, also acts as a protein lactyltransferase that mediates lactylation of lysine residues in target proteins, such as CGAS (PubMed:39322678). Acts as an inhibitor of cGAS/STING signaling by catalyzing lac

Mitochondrion

Combined oxidative phosphorylation deficiency 8

A mitochondrial disease characterized by a lethal infantile hypertrophic cardiomyopathy, generalized muscle dysfunction and some neurologic involvement. The liver is not affected.

Catalytic core component of RNA polymerase III (Pol III), a DNA-dependent RNA polymerase which synthesizes small non-coding RNAs using the four ribonucleoside triphosphates as substrates. Synthesizes 5S rRNA, snRNAs, tRNAs and miRNAs from at least 500 distinct genomic loci (PubMed:20413673, PubMed:33558766). Pol III-mediated transcription cycle proceeds through transcription initiation, transcription elongation and transcription termination stages. During transcription initiation, Pol III is rec

NucleusCytoplasm, cytosol

Leukodystrophy, hypomyelinating, 8, with or without oligodontia and/or hypogonadotropic hypogonadism

An autosomal recessive neurodegenerative disorder characterized by early childhood onset of cerebellar ataxia and mild intellectual disabilities associated with diffuse hypomyelination apparent on brain MRI. Variable features include oligodontia and/or hypogonadotropic hypogonadism.

One gap junction consists of a cluster of closely packed pairs of transmembrane channels, the connexons, through which materials of low MW diffuse from one cell to a neighboring cell. May play a role in myelination in central and peripheral nervous systems

Cell membraneCell junction, gap junction

Leukodystrophy, hypomyelinating, 2

An autosomal recessive hypomyelinating leukodystrophy with symptoms of Pelizaeus-Merzbacher disease. Clinically characterized by nystagmus, impaired motor development, ataxia, choreoathetotic movements, dysarthria, and progressive spasticity.

Plays a role in vesicle-mediated protein trafficking to lysosomal compartments including the endocytic membrane transport and autophagic pathways. Believed to act as a core component of the putative HOPS and CORVET endosomal tethering complexes which are proposed to be involved in the Rab5-to-Rab7 endosome conversion probably implicating MON1A/B, and via binding SNAREs and SNARE complexes to mediate tethering and docking events during SNARE-mediated membrane fusion. The HOPS complex is proposed

EndosomeLate endosome membraneLysosome membraneEarly endosomeCytoplasmic vesicleCytoplasmic vesicle, autophagosomeCytoplasmic vesicle, clathrin-coated vesicle

Leukodystrophy, hypomyelinating, 12

An autosomal recessive neurologic disorder characterized by developmental delay, spasticity, truncal hypotonia, acquired microcephaly, intellectual disability with variable seizure disorder, accompanied by thin corpus callosum, paucity of white matter and delayed myelination.

Component of the transition zone in primary cilia. Required for ciliogenesis

MembraneCell projection, cilium

Joubert syndrome 14

An autosomal recessive disorder characterized by severe intellectual disability, hypotonia, breathing abnormalities in infancy, and dysmorphic facial features. Neuroradiologically, it is characterized by cerebellar vermian hypoplasia/aplasia, thickened and reoriented superior cerebellar peduncles, and an abnormally large interpeduncular fossa, giving the appearance of a molar tooth on transaxial slices (molar tooth sign). Additional variable features include renal disease, abnormal eye movements, and postaxial polydactyly.

Hydrolyzes the non-reducing end N-acetyl-D-hexosamine and/or sulfated N-acetyl-D-hexosamine of glycoconjugates, such as the oligosaccharide moieties from proteins and neutral glycolipids, or from certain mucopolysaccharides (PubMed:11707436, PubMed:8123671, PubMed:8672428, PubMed:9694901). The isozyme S is as active as the isozyme A on the anionic bis-sulfated glycans, the chondroitin-6-sulfate trisaccharide (C6S-3), and the dermatan sulfate pentasaccharide, and the sulfated glycosphingolipid SM

Lysosome

GM2-gangliosidosis 1

An autosomal recessive lysosomal storage disease marked by the accumulation of GM2 gangliosides in the neuronal cells. It is characterized by GM2 gangliosides accumulation in the absence of HEXA activity, leading to neurodegeneration and, in the infantile form, death in early childhood. It exists in several forms: infantile (most common and most severe), juvenile and adult (late-onset).

Catalyzes the attachment of alanine to tRNA(Ala) in a two-step reaction: alanine is first activated by ATP to form Ala-AMP and then transferred to the acceptor end of tRNA(Ala) (PubMed:27622773, PubMed:27911835, PubMed:28493438, PubMed:33909043). Also edits incorrectly charged tRNA(Ala) via its editing domain (PubMed:27622773, PubMed:27911835, PubMed:28493438, PubMed:29273753). In presence of high levels of lactate, also acts as a protein lactyltransferase that mediates lactylation of lysine res

CytoplasmNucleus

Charcot-Marie-Tooth disease, axonal, type 2N

An axonal form of Charcot-Marie-Tooth disease, a disorder of the peripheral nervous system, characterized by progressive weakness and atrophy, initially of the peroneal muscles and later of the distal muscles of the arms. Charcot-Marie-Tooth disease is classified in two main groups on the basis of electrophysiologic properties and histopathology: primary peripheral demyelinating neuropathies (designated CMT1 when they are dominantly inherited) and primary peripheral axonal neuropathies (CMT2). Neuropathies of the CMT2 group are characterized by signs of axonal degeneration in the absence of obvious myelin alterations, normal or slightly reduced nerve conduction velocities, and progressive distal muscle weakness and atrophy.

E1-like activating enzyme involved in the 2 ubiquitin-like systems required for cytoplasm to vacuole transport (Cvt) and autophagy. Activates ATG12 for its conjugation with ATG5 as well as the ATG8 family proteins for their conjugation with phosphatidylethanolamine. Both systems are needed for the ATG8 association to Cvt vesicles and autophagosomes membranes. Required for autophagic death induced by caspase-8 inhibition. Facilitates LC3-I lipidation with phosphatidylethanolamine to form LC3-II w

CytoplasmPreautophagosomal structure

Spinocerebellar ataxia, autosomal recessive, 31

A form of spinocerebellar ataxia, a clinically and genetically heterogeneous group of cerebellar disorders due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCAR30 is characterized by global developmental delay, hypotonia, variably impaired intellectual and language development, ataxic gait, tremor, and dysarthria. Most affected individuals have optic atrophy. Additional features may include retinitis pigmentosa, sensorineural deafness, dysmorphic facial features, and possibly endocrine dysfunction.

Spinocerebellar ataxia, autosomal recessive, 27

A form of spinocerebellar ataxia, a clinically and genetically heterogeneous group of cerebellar disorders due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCAR27 is a progressive disease characterized by gait difficulties, eye movement abnormalities, dysarthria, and difficulty writing. Some patients may lose independent ambulation. Additional features include spasticity of the lower limbs and cognitive impairment.

DNA repair enzyme that can remove a variety of covalent adducts from DNA through hydrolysis of a 5'-phosphodiester bond, giving rise to DNA with a free 5' phosphate. Catalyzes the hydrolysis of dead-end complexes between DNA and the topoisomerase 2 (TOP2) active site tyrosine residue. The 5'-tyrosyl DNA phosphodiesterase activity can enable the repair of TOP2-induced DNA double-strand breaks/DSBs without the need for nuclease activity, creating a 'clean' DSB with 5'-phosphate termini that are re

NucleusNucleus, PML bodyNucleus, nucleolusCytoplasm

Spinocerebellar ataxia, autosomal recessive, 23

A form of spinocerebellar ataxia, a clinically and genetically heterogeneous group of cerebellar disorders due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCAR23 patients manifest epilepsy, intellectual disability, and gait ataxia.

Inositol 1,4,5-trisphosphate-gated calcium channel that, upon inositol 1,4,5-trisphosphate binding, mediates calcium release from the endoplasmic reticulum (ER) (PubMed:10620513, PubMed:27108797). Undergoes conformational changes upon ligand binding, suggesting structural flexibility that allows the channel to switch from a closed state, capable of interacting with its ligands such as 1,4,5-trisphosphate and calcium, to an open state, capable of transferring calcium ions across the ER membrane (

Endoplasmic reticulum membraneCytoplasmic vesicle, secretory vesicle membraneCytoplasm, perinuclear region

Spinocerebellar ataxia 15

Spinocerebellar ataxia is a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCA15 is an autosomal dominant cerebellar ataxia (ADCA). It is very slow progressing form with a wide range of onset, ranging from childhood to adult. Most patients remain ambulatory.

May be involved in the maintenance of mitochondrial organization and mitochondrial cristae structure

Mitochondrion intermembrane space

Frontotemporal dementia and/or amyotrophic lateral sclerosis 2

A neurodegenerative disorder characterized by frontotemporal dementia and/or amyotrophic lateral sclerosis in affected individuals. There is high intrafamilial variation. Frontotemporal dementia is characterized by frontal and temporal lobe atrophy associated with neuronal loss, gliosis, and dementia. Patients exhibit progressive changes in social, behavioral, and/or language function. Amyotrophic lateral sclerosis is characterized by the death of motor neurons in the brain, brainstem, and spinal cord, resulting in fatal paralysis.

Steroid hormone receptors are ligand-activated transcription factors that regulate eukaryotic gene expression and affect cellular proliferation and differentiation in target tissues (PubMed:19022849). Transcription factor activity is modulated by bound coactivator and corepressor proteins like ZBTB7A that recruits NCOR1 and NCOR2 to the androgen response elements/ARE on target genes, negatively regulating androgen receptor signaling and androgen-induced cell proliferation (PubMed:20812024). Tran

NucleusCytoplasm

Androgen insensitivity syndrome

An X-linked recessive form of pseudohermaphroditism due end-organ resistance to androgen. Affected males have female external genitalia, female breast development, blind vagina, absent uterus and female adnexa, and abdominal or inguinal testes, despite a normal 46,XY karyotype.

Ethanolaminephosphotransferase that catalyzes the transfer of phosphoethanolamine (PE) from CDP-ethanolamine to lipid acceptors, the final step in the synthesis of PE via the 'Kennedy' pathway (PubMed:17132865, PubMed:28052917, PubMed:29500230). PE is the second most abundant phospholipid of membranes in mammals and is involved in various membrane-related cellular processes (PubMed:17132865). The enzyme is critical for the synthesis of several PE species and also catalyzes the synthesis of plasm

Endoplasmic reticulum membrane

Spastic paraplegia 81, autosomal recessive

A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. SPG81 is a complicated form characterized by white matter abnormalities, hypomyelination with progressive white matter loss, delayed motor development, progressive spasticity, and impaired intellectual development and speech delay. Additional features may include bifid uvula, microcephaly, seizures, and variable ocular anomalies.

Acts as a Mg(2+) transporter. Can also transport other divalent cations such as Fe(2+), Sr(2+), Ba(2+), Zn(2+) and Co(2+) but to a much less extent than Mg(2+) (By similarity)

Cell membraneEarly endosome

Spastic paraplegia 6, autosomal dominant

A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body.

Kinesin motor with a plus-end-directed microtubule motor activity (By similarity). It is required for anterograde axonal transport of synaptic vesicle precursors (PubMed:33880452). Also required for neuronal dense core vesicles (DCVs) transport to the dendritic spines and axons. The interaction calcium-dependent with CALM1 increases vesicle motility and interaction with the scaffolding proteins PPFIA2 and TANC2 recruits DCVs to synaptic sites

Cytoplasm, cytoskeletonCell projection, neuron projectionCell projection, axonCytoplasm, perinuclear regionSynapseCytoplasmic vesicle, secretory vesicle, neuronal dense core vesicle membrane

Spastic paraplegia 30A, autosomal dominant

A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. Some SPG30A patients have a pure form of the disorder, limited to spastic paraplegia, whereas others may have a complicated form that includes additional features such as cognitive dysfunction, learning disabilities, peripheral sensorimotor neuropathy, urinary sphincter problems, and/or cerebellar atrophy. SPG30A is characterized by onset in the first or second decades of unsteady spastic gait and hyperreflexia of the lower limbs. Inheritance is autosomal dominant.

Motor required for the retrograde transport of Golgi vesicles to the endoplasmic reticulum. Has a microtubule plus end-directed motility

Cytoplasm, cytoskeleton

Spastic ataxia 2, autosomal recessive

A neurologic disorder characterized by cerebellar ataxia, dysarthria, and variable spasticity of the lower limbs. Cognition is not affected.

Catalyzes the reversible conversion of ribose-5-phosphate to ribulose 5-phosphate and participates in the first step of the non-oxidative branch of the pentose phosphate pathway

Ribose 5-phosphate isomerase deficiency

An autosomal recessive inborn error of polyols metabolism characterized by highly elevated level of ribitol and arabitol in brain and body fluids. Clinical features include leukoencephalopathy, psychomotor retardation from early life, neurologic regression, and a mild sensorimotor neuropathy.

Required for peroxisome membrane biogenesis. May play a role in early stages of peroxisome assembly. Can recruit other peroxisomal proteins, such as PEX3 and PMP34, to de novo peroxisomes derived from the endoplasmic reticulum (ER). May function as receptor for PEX3

Peroxisome membrane

Peroxisome biogenesis disorder complementation group 9

A peroxisomal disorder arising from a failure of protein import into the peroxisomal membrane or matrix. The peroxisome biogenesis disorders (PBD group) are genetically heterogeneous with at least 14 distinct genetic groups as concluded from complementation studies. Include disorders are: Zellweger syndrome (ZWS), neonatal adrenoleukodystrophy (NALD), infantile Refsum disease (IRD), and classical rhizomelic chondrodysplasia punctata (RCDP). ZWS, NALD and IRD are distinct from RCDP and constitute a clinical continuum of overlapping phenotypes known as the Zellweger spectrum (PBD-ZSS).

Component of the PEX1-PEX6 AAA ATPase complex, a protein dislocase complex that mediates the ATP-dependent extraction of the PEX5 receptor from peroxisomal membranes, an essential step for PEX5 recycling (PubMed:16314507, PubMed:16854980, PubMed:21362118, PubMed:29884772). Specifically recognizes PEX5 monoubiquitinated at 'Cys-11', and pulls it out of the peroxisome lumen through the PEX2-PEX10-PEX12 retrotranslocation channel (PubMed:29884772). Extraction by the PEX1-PEX6 AAA ATPase complex is

Cytoplasm, cytosolPeroxisome membraneCell projection, cilium, photoreceptor outer segment

Peroxisome biogenesis disorder complementation group 4

A peroxisomal disorder arising from a failure of protein import into the peroxisomal membrane or matrix. The peroxisome biogenesis disorders (PBD group) are genetically heterogeneous with at least 14 distinct genetic groups as concluded from complementation studies. Include disorders are: Zellweger syndrome (ZWS), neonatal adrenoleukodystrophy (NALD), infantile Refsum disease (IRD), and classical rhizomelic chondrodysplasia punctata (RCDP). ZWS, NALD and IRD are distinct from RCDP and constitute a clinical continuum of overlapping phenotypes known as the Zellweger spectrum (PBD-ZSS).

Component of a retrotranslocation channel required for peroxisome organization by mediating export of the PEX5 receptor from peroxisomes to the cytosol, thereby promoting PEX5 recycling (PubMed:24662292, PubMed:9354782, PubMed:9632816). The retrotranslocation channel is composed of PEX2, PEX10 and PEX12; each subunit contributing transmembrane segments that coassemble into an open channel that specifically allows the passage of PEX5 through the peroxisomal membrane (By similarity). PEX12 also re

Peroxisome membrane

Peroxisome biogenesis disorder complementation group 3

A peroxisomal disorder arising from a failure of protein import into the peroxisomal membrane or matrix. The peroxisome biogenesis disorders (PBD group) are genetically heterogeneous with at least 14 distinct genetic groups as concluded from complementation studies. Include disorders are: Zellweger syndrome (ZWS), neonatal adrenoleukodystrophy (NALD), infantile Refsum disease (IRD), and classical rhizomelic chondrodysplasia punctata (RCDP). ZWS, NALD and IRD are distinct from RCDP and constitute a clinical continuum of overlapping phenotypes known as the Zellweger spectrum (PBD-ZSS).

Component of the PEX1-PEX6 AAA ATPase complex, a protein dislocase complex that mediates the ATP-dependent extraction of the PEX5 receptor from peroxisomal membranes, an essential step for PEX5 recycling (PubMed:11439091, PubMed:16314507, PubMed:16854980, PubMed:21362118, PubMed:29884772). Specifically recognizes PEX5 monoubiquitinated at 'Cys-11', and pulls it out of the peroxisome lumen through the PEX2-PEX10-PEX12 retrotranslocation channel (PubMed:29884772). Extraction by the PEX1-PEX6 AAA A

Cytoplasm, cytosolPeroxisome membrane

Peroxisome biogenesis disorder complementation group 1

A peroxisomal disorder arising from a failure of protein import into the peroxisomal membrane or matrix. The peroxisome biogenesis disorders (PBD group) are genetically heterogeneous with at least 14 distinct genetic groups as concluded from complementation studies. Include disorders are: Zellweger syndrome (ZWS), neonatal adrenoleukodystrophy (NALD), infantile Refsum disease (IRD), and classical rhizomelic chondrodysplasia punctata (RCDP). ZWS, NALD and IRD are distinct from RCDP and constitute a clinical continuum of overlapping phenotypes known as the Zellweger spectrum (PBD-ZSS).

CytoplasmNucleus

PEHO syndrome

An autosomal recessive syndrome characterized by progressive encephalopathy, lack of psychomotor development, severe intellectual disability, early onset epileptic seizures, optic nerve/cerebellar atrophy, pedal edema, and early death.

Catalytic component of the m-AAA protease, a protease that plays a key role in proteostasis of inner mitochondrial membrane proteins, and which is essential for axonal and neuron development (PubMed:19748354, PubMed:28396416, PubMed:29932645, PubMed:30683687, PubMed:31327635, PubMed:37917749, PubMed:38157846). AFG3L2 possesses both ATPase and protease activities: the ATPase activity is required to unfold substrates, threading them into the internal proteolytic cavity for hydrolysis into small pe

Mitochondrion inner membrane

Spinocerebellar ataxia 28

Spinocerebellar ataxia is a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCA28 is an autosomal dominant cerebellar ataxia (ADCA) with a slow progressive course and no evidence of sensory involvement or cognitive impairment.

Promotes matrix assembly (By similarity). Involved in the organization of skeletal muscles and in the formation of neuromuscular junctions (Probable)

Secreted, extracellular space, extracellular matrix, basement membrane

Neuronopathy, hereditary motor, autosomal recessive 7

An autosomal recessive, neuromyopathic disorder that manifests in childhood or adulthood with proximal and distal muscle weakness predominantly of the lower limbs. Affected individuals have difficulty climbing stairs and problems standing on the heels. Most patients have foot deformities, and some may have leg muscle atrophy. Muscle biopsy and electrophysiologic studies are consistent with both a myopathic process and an axonal motor neuropathy.

High-affinity Na(+)-coupled choline transmembrane symporter (PubMed:11027560, PubMed:11068039, PubMed:12237312, PubMed:12969261, PubMed:17005849, PubMed:23132865, PubMed:23141292, PubMed:27569547). Functions as an electrogenic, voltage-dependent transporter with variable charge/choline stoichiometry (PubMed:17005849). Choline uptake and choline-induced current is also Cl(-)-dependent where Cl(-) is likely a regulatory ion rather than cotransported ion (PubMed:11068039, PubMed:12237312, PubMed:17

Presynaptic cell membraneCell projection, axonEarly endosome membraneCytoplasmic vesicle, secretory vesicle, synaptic vesicle membrane

Neuronopathy, distal hereditary motor, autosomal dominant 7

A form of distal hereditary motor neuronopathy, a heterogeneous group of neuromuscular disorders caused by selective degeneration of motor neurons in the anterior horn of the spinal cord, without sensory deficit in the posterior horn. The overall clinical picture consists of a classical distal muscular atrophy syndrome in the legs without clinical sensory loss. The disease starts with weakness and wasting of distal muscles of the anterior tibial and peroneal compartments of the legs. Later on, weakness and atrophy may expand to the proximal muscles of the lower limbs and/or to the distal upper limbs. HMND7 is characterized by onset in the second decade of progressive distal muscle wasting and weakness affecting the upper and lower limbs and resulting in walking difficulties and hand grip. There is significant muscle atrophy of the hands and lower limbs. The disorder is associated with vocal cord paresis due to involvement of the tenth cranial nerve.

Catalyzes the ATP-dependent ligation of glycine to the 3'-end of its cognate tRNA, via the formation of an aminoacyl-adenylate intermediate (Gly-AMP) (PubMed:17544401, PubMed:24898252, PubMed:28675565). Also produces diadenosine tetraphosphate (Ap4A), a universal pleiotropic signaling molecule needed for cell regulation pathways, by direct condensation of 2 ATPs. Thereby, may play a special role in Ap4A homeostasis (PubMed:19710017)

CytoplasmCell projection, axonSecretedSecreted, extracellular exosomeMitochondrion

Charcot-Marie-Tooth disease, axonal, type 2D

A dominant axonal form of Charcot-Marie-Tooth disease, a disorder of the peripheral nervous system, characterized by progressive weakness and atrophy, initially of the peroneal muscles and later of the distal muscles of the arms. Charcot-Marie-Tooth disease is classified in two main groups on the basis of electrophysiologic properties and histopathology: primary peripheral demyelinating neuropathies (designated CMT1 when they are dominantly inherited) and primary peripheral axonal neuropathies (CMT2). Neuropathies of the CMT2 group are characterized by signs of axonal degeneration in the absence of obvious myelin alterations, normal or slightly reduced nerve conduction velocities, and progressive distal muscle weakness and atrophy.

Bifunctional enzyme that catalyzes the fourth step of the coenzyme A biosynthetic pathway, the adenylation of 4'-phosphopantetheine, and the fifth step, the phosphorylation of dephospho-CoA to CoA

Cytoplasm, cytosolMitochondrion matrix

Neurodegeneration with brain iron accumulation 6

A neurodegenerative disorder associated with iron accumulation in the brain, primarily in the basal ganglia. It is characterized by progressive motor and cognitive dysfunction beginning in childhood or young adulthood. Patients show extrapyramidal motor signs, such as spasticity, dystonia, and parkinsonism.

Stores iron in a soluble, non-toxic, readily available form. Important for iron homeostasis. Iron is taken up in the ferrous form and deposited as ferric hydroxides after oxidation. Also plays a role in delivery of iron to cells. Mediates iron uptake in capsule cells of the developing kidney (By similarity). Delivery to lysosomes by the cargo receptor NCOA4 for autophagic degradation and release or iron (PubMed:24695223)

Cytoplasmic vesicle, autophagosomeCytoplasmAutolysosome

Hyperferritinemia with or without cataract

An autosomal dominant disease characterized by elevated level of ferritin in serum and tissues, and early-onset bilateral cataract. Cataracts may be subclinical in some patients.

Involved in regulating cell motility and cell-matrix interactions. May inhibit cell growth through suppression of cell proliferation (PubMed:15885354, PubMed:15917256). In glia, associates and targets CLCN2 at astrocytic processes and myelinated fiber tracts where it may regulate transcellular chloride flux involved in neuron excitability (PubMed:22405205)

CytoplasmCell membrane

Megalencephalic leukoencephalopathy with subcortical cysts 2A

A neurodegenerative disorder characterized by infantile-onset macrocephaly and later onset of motor deterioration, with ataxia and spasticity, seizures, and cognitive decline of variable severity. The brain appears swollen on magnetic resonance imaging with white-matter abnormalities and subcortical cysts, in all stages of the disease.