Sengers syndrome (OMIM #212350) is a rare autosomal recessive disorder caused by mutations in the AGK gene and characterized by hypertrophic cardiomyopathy, congenital cataracts, and mitochondrial myopathy, including muscle weakness and lactic acidosis after exercise [16]. This evidence concerns the gene AGK and Congenital cataract - hypertrophic cardiomyopathy - mitochondrial myopathy.