AGK and skeletal muscle disorder: AGK mutations cause Sengers syndrome (MIM #212350), a rare, autosomal recessive mitochondrial disorder associated with congenital cataracts, hypertrophic cardiomyopathy, lactic acidosis and skeletal myopathy [41,42] Loss of AGK perturbs TIMM22 complex stability, disrupting carrier protein import and dampening the rate of mitochondrial respiration and metabolic flux through the TCA cycle [43,44].