MTO1 mutations cause combined oxidative phosphorylation deficiency 10 (COXPD10), presenting with infantile hypertrophic cardiomyopathy and lactic acidosis, while GTPBP3 mutations cause COXPD23, characterized by early childhood hypertrophic cardiomyopathy and neurological symptoms [140]. The gene discussed is GTPBP3; the disease is Mitochondrial disease with hypertrophic cardiomyopathy.