ATP5F1A and hyperinsulinemic hypoglycemia, familial, 4: Mutations of the ATP5A1 gene, encoding the alpha subunit of the ATP synthase F1 fraction, are associated with two phenotypes of human disease: mitochondrial complex V (ATP synthase) deficiency, nuclear type 4 (MC5DN4, MIM 615228), which is an autosomal recessive, fatal form of infantile encephalopathy, and combined oxidative phosphorylation deficiency 22 (COXPD22, MIM 616045), also an autosomal recessive disorder, resulting in early death.