MT-ATP6 and maternally-inherited Leigh syndrome: In humans, 8 missense and two frame shift mutations lead to ATP6 impairment and are known to cause the related mitochondrial disorders: maternally inherited Leigh's syndrome (MILS), neuropathy, ataxia, and retinitis pigmentosa (NARP), and familial bilateral striatal necrosis (FBSN) [10], [11], [12], [13], [14], [15], [16], [17], [18].