M.P.1.12 Progressive encephalopathy and complex I deficiency associated with novel mutations in MTND1

Abstract

Complex I of the oxidative phosphorylation system is composed of at least 43 subunits, seven of which are encoded by mitochondrial DNA (mtDNA). Pathogenic mutations that have been identified in mtDNA encoded subunits of complex I include missense mutations associated with Leber hereditary optic neuropathy and encephalopathies such as MELAS and Leigh syndromes. In this study, we have investigated two children with complex I deficiency in muscle mitochondria. Patient 1 had a lactic acidosis in the newborn period and in early age developed profound learning disability.