They include MELAS (mitochondrial encephalomyopathy and lactic acidosis with stroke-like episodes), MERRF (myoclonic epilepsy and ragged-red fiber), TRMU-dependent acute infantile liver failure and hypertrophic cardiomyopathies dependent on MTO1 and GTPBP3. Here, GTPBP3 is linked to hypertrophic cardiomyopathy.