Hypertrophic obstructive cardiomyopathy due to a novel T-to-A transition at codon 624 in the β-myosin heavy chain (β-MHC) gene possibly related to the sudden death

Many missense mutations in the β-myosin heavy chain have been reported in patients with hypertrophic obstructive cardiomyopathy (HOCM). However, the controversy is present whether the mutation accompanying the change of electric charge is related with poorer prognosis. The proband, a 48-year-old female, of the family was diagnosed clinically as HOCM, and a structural analysis of the cardiac β-MHC gene showed that the proband and her junior daughter had a novel mutation with T to A transition in codon 624 replacing tyrosine with asparagine, which was not present in her husband, elder daughter and son. The probandʹs husband, son and two daughters were healthy except that the ECG of junior daughter (15-year-old) showed complete right bundle branch block. Probandʹs mother died suddenly after the delivery of the proband and the proband also collapsed suddenly. The occurrence of sudden death in proband and her mother suggested that HOCM with this novel mutation might be associated with a high risk of sudden death irrespective of the absence of charge alteration.