DNAJC30 is a mitochondrial Hsp40 chaperone protein enriched in neurons that regulates mitochondrial respiration and ATP synthesis. It associates with the ATP synthase complex and facilitates ATP synthesis 1. DNAJC30 functions as a critical regulator of mitochondrial complex I integrity, acting as a chaperone protein involved in the turnover of complex I N-module subunits 1. It facilitates the degradation of N-module subunits damaged by oxidative stress, enabling efficient exchange of assembled respiratory chain subunits and maintaining complex I functional efficiency 1. DNAJC30 dysfunction causes autosomal recessive Leber hereditary optic neuropathy (arLHON), a primary neurodegenerative disorder characterized by acute vision loss and optic nerve damage 23. The c.152A>G;p.(Tyr51Cys) missense variant represents a founder mutation accounting for the majority of disease alleles, particularly in European populations 45. ArLHON patients exhibit clinical features indistinguishable from mitochondrial LHON, including male predominance, incomplete penetrance, and responsivity to idebenone treatment 12. DNAJC30 mutations also associate with Leigh syndrome, a severe pediatric mitochondrial disorder 26. The disease mechanism involves impaired complex I repair due to defective subunit turnover and increased susceptibility to oxidative damage 1.