NADH Dehydrogenase Fe-S Protein 6(NDUFS6) is a subunit of the NADH: ubiquinone oxidoreductase(complex I), which is the 1st enzyme complex in the electron transport chain of the mitochondria. This complex operates in the transfer of electrons from NADH to the respiratory chain. NDUFS6 is one of seven subunits in the iron-sulfur protein segment. DNA alterations in NDUFS6 are the cause for mitochondrial complex I deficiency, a disease which results in an extensive assortment of clinical disorders, like adult-onset neurodegenerative disorders and neonatal disease.