It has numerous etiologies, including sarcomeric disorders, inborn metabolic errors, RASopathies, mitochondrial myopathies, and glycogen and lysosomal storage disorders in children ​[2,3,11]. Several genes have been implicated in the pathogenesis of HCM, including myosin-binding protein C3 (MYBPC3) and beta myosin heavy chain 7 (MYH7) gene mutations, that correspond to sarcomeric (thick filament protein) and thin filament protein-encoding genes such as TNNT2 and TNNI3 [2,3,12]. The gene discussed is MYBPC3; the disease is Mitochondrial myopathy.