COASY protein associated neurodegeneration is a rare, progressive autosomal recessive neuroferritinopathy due to pathogenic mutations in the COASY gene, coding for the mitochondrial located coenzyme A synthase. Clinical manifestations include seizures, progressive spasticity, dystonia, neuropathy, cognitive decline and neuropsychiatric abnormalities. Both foetal and childhood onset phenotypes are described. We report three patients with COASY protein associated neurodegeneration who were identified on newborn screening with a dried bloodspot acylcarnitine pattern consistent with carnitine palmitoyltransferase 1a deficiency, that is, an elevated ratio of free carnitine (C0) to the sum of palmitoylcarnitine (C16) and octanoylcarnitine (C18):[C0/(C16+C18)]. Two siblings, who died in infancy, displayed neurological features from birth, with magnetic resonance imaging of the brain displaying immature cortical sulcation, parenchymal atrophy and pontocerebellar hypoplasia. The third patient presented with global developmental delay, pyramidal signs and seizures with brain magnetic resonance imaging at age 15 months demonstrating a thin corpus callosum, symmetric diffusion restriction throughout the basal ganglia and evidence of deposition in the globus pallidus. This report demonstrates that phenotypes of COASY protein associated neurodegeneration should be included in the differential diagnosis of dried blood spot acylcarnitine pattern suggestive of carnitine palmitoyltransferase 1a deficiency and may represent new potential for early diagnosis.

Coenzyme A (CoA) is a crucial metabolite involved in various biological processes, encompassing lipid metabolism, regulation of mitochondrial function, and membrane modeling. CoA deficiency is associated with severe human diseases, such as Pantothenate Kinase-Associated Neurodegeneration (PKAN) and CoASY protein-associated neurodegeneration (CoPAN), which are linked to genetic mutations in Pantothenate Kinase 2 (PANK2) and CoA Synthase (CoASY). Although the association between CoA deficiency and mitochondrial dysfunction has been established, the underlying molecular alterations and mechanisms remain largely elusive. In this study, we investigated the detailed changes resulting from the functional decline of CoASY using the Drosophila model. Our findings revealed that a reduction of CoASY in muscle and brain led to degenerative phenotypes and apoptosis, accompanied by impaired mitochondrial integrity. The release of mitochondrial DNA was notably augmented, while the assembly and activity of mitochondrial electron transport chain (ETC) complexes, particularly complex I and III, were diminished. Consequently, this resulted in decreased ATP generation, rendering the fly more susceptible to energy insufficiency. Our findings suggest that compromised mitochondrial integrity and energy supply play a crucial role in the pathogenesis associated with CoA deficiency, thereby implying that enhancing mitochondrial integrity can be considered a potential therapeutic strategy in future interventions.

COASY protein-associated neurodegeneration (CoPAN) is a rare autosomal recessive disorder within the Neurodegeneration with Brain Iron Accumulation spectrum, resulting from mutations in COASY. This gene encodes the bifunctional enzyme essential for the final steps of coenzyme A biosynthesis. To elucidate the pathophysiology and iron dyshomeostasis underlying CoPAN, we analyzed fibroblasts and human induced pluripotent stem (hiPS)-derived astrocytes from two patients carrying distinct COASY mutations. Our findings reveal that CoPAN fibroblasts display altered iron homeostasis, characterized by iron aggregates, elevated cytosolic labile iron pool, and impaired tubulin acetylation. Patients hiPS-derived astrocytes showed mitochondrial morphological abnormalities and compromised vesicular trafficking. Notably, both cell types demonstrated evidence of ferroptosis, but the astrocytes exhibited more pronounced iron accumulation and lipid peroxidation. These results demonstrate that astrocytes may more accurately recapitulate the pathological phenotype of CoPAN compared to fibroblasts. Interestingly, astrocytes exhibited different levels of iron accumulation concomitant with cellular senescence, indicating a possible role of iron-induced cellular senescence. This finding suggests that the accumulation of cytosolic iron, possibly caused by mitochondrial dysfunction, actively promotes senescence. Our data emphasize the potential therapeutic efficacy of drugs that enhance mitochondrial functionality to attenuate the effects of CoPAN. The purpose of this overview is to: 1.. Briefly describe the clinical characteristics of neurodegeneration with brain iron accumulation (NBIA); 2.. Review the genetic causes of NBIA; 3.. Review the differential diagnosis of NBIA with a focus on genetic conditions; 4.. Provide an evaluation strategy to identify the genetic cause of NBIA in a proband (when possible); 5.. Review high-level management of NBIA; 6.. Inform genetic counseling of family members of an individual with NBIA.

Coenzyme A (CoA), which is widely distributed and vital for cellular metabolism, is a critical molecule essential in both synthesizing and breaking down key energy sources in the body. Inborn errors of metabolism in the cellular de novo biosynthetic pathway of CoA have been linked to human genetic disorders, emphasizing the importance of this pathway. The COASY gene encodes the bifunctional enzyme CoA synthase, which catalyzes the last two reactions of the CoA biosynthetic pathway and serves as one of the rate-limiting components of the pathway. Recessive variants of this gene cause an exceptionally rare and devastating disease called COASY protein-associated neurodegeneration (CoPAN) while complete loss-of-function variants in COASY have been identified in fetuses/neonates with Pontocerebellar Hypoplasia type 12 (PCH 12). Understanding why the different symptoms emerge in these disorders and what determines the development of one syndrome over the other is still not achieved. To shed light on the pathogenesis, we generated a new conditional animal model in which Coasy was deleted under the control of the human GFAP promoter. We used this mouse model to investigate how defects in the CoA biosynthetic pathway affect brain development. This model showed a broad spectrum of severity of the in vivo phenotype, ranging from very short survival (less than 2 weeks) to normal life expectancy in some animals. Surviving mice displayed a behavioral phenotype with sensorimotor defects. Ex vivo histological analysis revealed variable but consistent cerebral and cerebellar cortical hypoplasia, in parallel with a broad astrocytic hyper-proliferation in the cerebral cortex. In addition, primary astrocytes derived from this model exhibited lipid peroxidation, iron dyshomeostasis, and impaired mitochondrial respiration. Notably, Coasy ablation in radial glia and astrocytic lineage triggers abnormal neuronal development and chronic neuroinflammation, offering new insights into disease mechanisms.

COASY, the gene encoding the bifunctional enzyme CoA synthase, which catalyzes the last two reactions of cellular de novo coenzyme A (CoA) biosynthesis, has been linked to two exceedingly rare autosomal recessive disorders, such as COASY protein-associated neurodegeneration (CoPAN), a form of neurodegeneration with brain iron accumulation (NBIA), and pontocerebellar hypoplasia type 12 (PCH12). We aimed to expand the phenotypic spectrum and gain insights into the pathogenesis of COASY-related disorders. Patients were identified through targeted or exome sequencing. To unravel the molecular mechanisms of disease, RNA sequencing, bioenergetic analysis, and quantification of critical proteins were performed on fibroblasts. We identified five new individuals harboring novel COASY variants. While one case exhibited classical CoPAN features, the others displayed atypical symptoms such as deafness, language and autism spectrum disorders, brain atrophy, and microcephaly. All patients experienced epilepsy, highlighting its potential frequency in COASY-related disorders. Fibroblast transcriptomic profiling unveiled dysregulated expression in genes associated with mitochondrial respiration, responses to oxidative stress, transmembrane transport, various cellular signaling pathways, and protein translation, modification, and trafficking. Bioenergetic analysis revealed impaired mitochondrial oxygen consumption in COASY fibroblasts. Despite comparable total CoA levels to control cells, the amounts of mitochondrial 4'-phosphopantetheinylated proteins were significantly reduced in COASY patients. These results not only extend the clinical phenotype associated with COASY variants but also suggest a continuum between CoPAN and PCH12. The intricate interplay of altered cellular processes and signaling pathways provides valuable insights for further research into the pathogenesis of COASY-associated diseases.