Pt250, a girl with tachypnea, hypertrophic cardiomyopathy, adrenal insufficiency, hearing loss, and combined respiratory chain complex deficiencies (I, II, III, and IV), harbored a homozygous mutation c.398G>T (p.G133V) in QRSL1 (NM_018292) (Figs 3D and S14). This evidence concerns the gene QRSL1 and hypertrophic cardiomyopathy.