Another case of human disease gene is the NADH-ubiquinone oxidoreductase flavoprotein 1 (NDUFV1),which encodes a 51 kD subunit of complex I of the mitochondrial respiratory chain, and mutation of this gene leads to a mitochondrial complex I deficiency in human [61], [62]. The gene discussed is NDUFV1; the disease is hyperinsulinemic hypoglycemia, familial, 4.