Epilepsy, familial focal, with variable foci 4

An autosomal dominant form of epilepsy characterized by focal seizures arising from different cortical regions, including the temporal, frontal, parietal, and occipital lobes. Seizure types commonly include temporal lobe epilepsy, frontal lobe epilepsy, and nocturnal frontal lobe epilepsy. Some patients may have intellectual disability or autism spectrum disorders. Seizure onset usually occurs in the first or second decades, although later onset has been reported, and there is phenotypic variability within families. A subset of patients have structural brain abnormalities. Penetrance of the disorder is incomplete. FFEVF4 is characterized by onset of focal seizures in the first years of life.

Lissencephaly 2

A classic type lissencephaly associated with ataxia, intellectual disability, seizures and abnormalities of the cerebellum, hippocampus and brainstem.

Cone-rod synaptic disorder, congenital non-progressive

A non-progressive retinal disorder characterized by stable low vision, nystagmus, photophobia, a normal or near-normal fundus appearance, and no night blindness.

Generalized epilepsy with febrile seizures plus 2

A rare autosomal dominant, familial condition with incomplete penetrance and large intrafamilial variability. Patients display febrile seizures persisting sometimes beyond the age of 6 years and/or a variety of afebrile seizure types. This disease combines febrile seizures, generalized seizures often precipitated by fever at age 6 years or more, and partial seizures, with a variable degree of severity.

Intellectual developmental disorder, autosomal dominant 60, with seizures

An autosomal dominant disorder characterized by global developmental delay apparent in the first six months of life, followed by onset of seizures between 21 months and 4 years. Disease features include moderate-to-severe intellectual disability, poor speech, delayed walking, and ataxia.

Epilepsy, idiopathic generalized 6

A disorder characterized by recurring generalized seizures in the absence of detectable brain lesions and/or metabolic abnormalities. Generalized seizures arise diffusely and simultaneously from both hemispheres of the brain.

Epilepsy, childhood absence 4

A subtype of idiopathic generalized epilepsy characterized by an onset at age 6-7 years, frequent absence seizures (several per day) and bilateral, synchronous, symmetric 3-Hz spike waves on EEG. Tonic-clonic seizures often develop in adolescence. Absence seizures may either remit or persist into adulthood.

Developmental and epileptic encephalopathy 67

A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE67 is an autosomal dominant form characterized by onset of seizures in infancy. Later onset of seizures in childhood may occur in some patients.

Intellectual developmental disorder, X-linked 98

A disorder characterized by significantly below average general intellectual functioning associated with impairments in adaptive behavior and manifested during the developmental period. XLID98 patients show delayed psychomotor development, absent or poor speech development, and postnatal growth retardation, often with microcephaly. Some patients show autistic behavioral features, such as stereotypic hand movements and repetitive behaviors. Additional, more variable features include spasticity, axial hypotonia, seizures, drooling, gastroesophageal reflux, and lack of sphincter control.

GLUT1 deficiency syndrome 1

A neurologic disorder showing wide phenotypic variability. The most severe 'classic' phenotype comprises infantile-onset epileptic encephalopathy associated with delayed development, acquired microcephaly, motor incoordination, and spasticity. Onset of seizures, usually characterized by apneic episodes, staring spells, and episodic eye movements, occurs within the first 4 months of life. Other paroxysmal findings include intermittent ataxia, confusion, lethargy, sleep disturbance, and headache. Varying degrees of cognitive impairment can occur, ranging from learning disabilities to severe intellectual disability.

Developmental and epileptic encephalopathy 37

A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE37 is an autosomal recessive, severe form manifesting in the first years of life. Affected individuals show hyperkinetic movement disorder with choreoathetosis, spasticity, rigidity, intellectual disability, absent speech, and impaired volitional movements.

Intellectual developmental disorder, autosomal dominant 5

A disorder characterized by significantly below average general intellectual functioning associated with impairments in adaptive behavior and manifested during the developmental period. MRD5 patients show global developmental delay with delayed motor development, hypotonia, moderate-to-severe intellectual disability, and severe language impairment. Epilepsy and autism can be present in some patients.

Spinocerebellar ataxia 6

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. SCA6 is an autosomal dominant cerebellar ataxia (ADCA), mainly caused by expansion of a CAG repeat in the coding region of CACNA1A. There seems to be a correlation between the repeat number and earlier onset of the disorder.

Rolandic epilepsy, impaired intellectual development, and speech dyspraxia, X-linked

A condition characterized by the association of rolandic seizures with oral and speech dyspraxia, and intellectual disability. Rolandic seizures occur during a period of significant brain maturation. During this time, dysfunction of neural network activities such as focal discharges may be associated with specific developmental disabilities resulting in specific cognitive impairments of language, visuo-spatial abilities or attention.

Epilepsy, familial temporal lobe, 8

A focal form of epilepsy characterized by recurrent seizures that arise from foci within the temporal lobe. Seizures are usually accompanied by sensory symptoms, most often auditory in nature.

Epilepsy, nocturnal frontal lobe, 3

An autosomal dominant focal epilepsy characterized by nocturnal seizures with hyperkinetic automatisms and poorly organized stereotyped movements.

Epilepsy, nocturnal frontal lobe, 1

An autosomal dominant focal epilepsy characterized by nocturnal seizures with hyperkinetic automatisms and poorly organized stereotyped movements.

Developmental and epileptic encephalopathy 14

A rare epileptic encephalopathy of infancy that combines pharmacoresistant seizures with developmental delay. This severe neurologic disorder is characterized by onset in the first 6 months of life of refractory focal seizures and arrest of psychomotor development. Ictal EEG shows discharges that arise randomly from various areas of both hemispheres and migrate from one brain region to another.

Developmental and epileptic encephalopathy 94

A form of epileptic encephalopathy, a heterogeneous group of early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE94 is an autosomal dominant, severe form characterized by onset of multiple seizure types in the first few years of life.

Epilepsy, familial temporal lobe, 1

A focal form of epilepsy characterized by recurrent seizures that arise from foci within the temporal lobe. Seizures are usually accompanied by sensory symptoms, most often auditory in nature.

Developmental and epileptic encephalopathy 31A

An autosomal dominant epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent.

Myoclonic-atonic epilepsy

A form of epilepsy characterized by myoclonic-atonic and absence seizures, appearing in early childhood. Patients have delayed development before the onset of seizures and show varying degrees of intellectual disability following seizure onset.

Epilepsy, familial focal, with variable foci 1

An autosomal dominant form of epilepsy characterized by focal seizures arising from different cortical regions in different family members. Many patients have an aura and show automatisms during the seizures, whereas others may have nocturnal seizures. There is often secondary generalization. Some patients show abnormal interictal EEG, and some patients may have intellectual disability or autism spectrum disorders. Seizure onset usually occurs in the first or second decades, although later onset has been reported, and there is phenotypic variability within families. Penetrance of the disorder is incomplete.

Epilepsy, childhood absence 5

A subtype of idiopathic generalized epilepsy characterized by an onset at age 6-7 years, frequent absence seizures (several per day) and bilateral, synchronous, symmetric 3-Hz spike waves on EEG. Tonic-clonic seizures often develop in adolescence. Absence seizures may either remit or persist into adulthood.

Paroxysmal non-kinesigenic dyskinesia 3 with or without generalized epilepsy

An autosomal dominant neurologic disorder characterized by absence seizures, generalized tonic-clonic seizures, paroxysmal nonkinesigenic dyskinesia and involuntary dystonic or choreiform movements. Onset is usually in childhood. Patients may have seizures only, dyskinesia only, or both.

Familial infantile myoclonic epilepsy

A subtype of idiopathic epilepsy starting in early infancy and manifesting as myoclonic seizures, febrile convulsions, and tonic-clonic seizures.

Epilepsy, nocturnal frontal lobe, 4

An autosomal dominant focal epilepsy characterized by nocturnal seizures associated with fear sensation, tongue movements, and nocturnal wandering, closely resembling nightmares and sleep walking.

Epilepsy, focal, with speech disorder and with or without impaired intellectual development

An autosomal dominant, highly variable neurologic disorder. Features range from severe early-onset seizures associated with delayed psychomotor development, persistent speech difficulties, and intellectual disability to a more benign entity characterized by childhood onset of mild or asymptomatic seizures associated with transient speech difficulties followed by remission of seizures in adolescence and normal psychomotor development. The disorder encompasses several clinical entities, including Landau-Kleffner syndrome, epileptic encephalopathy with continuous spike and wave during slow-wave sleep, autosomal dominant rolandic epilepsy, intellectual disability and speech dyspraxia, and benign epilepsy with centrotemporal spikes.

Developmental and epileptic encephalopathy 74

A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE74 is an autosomal dominant form with onset in the first year of life.