Mitochondrial Complex I Deficiency, Nuclear Types 1–37 (MC1DN) and Mitochondrial Type 1 (MC1DM1)

Mitochondrial complex I deficiency is a genetic disorder caused by a mutation in both nuclear and mitochondrial genes coding for structural subunits of mitochondrial oxidative phosphorylation system I (OXPHOS complex) and associated factors involved in the assembly and function of the complex, leading to a wide array of clinical manifestation including Leigh syndrome, MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes) syndrome, and LHON (Leber’s hereditary optic neuropathy).