A case of familial hypertrophic cardiomyopathy emphasizes the importance of parallel screening of multiple disease genes

Abstract

A 2-year-old boy, who underwent clinical evaluation due to the presence of a developmental disorder, revealed upon physical examination a loud systolic murmur, electrocardiography (ECG) signs of hypertrophy and transthoracic echocardiography (TTE) massive hypertrophy of the left ventricle. Thus, the diagnosis of a severe hypertrophic cardiomyopathy (HCM) was obvious. In the family history, a preexisting symptomatic HCM of the mother was known. The clinical examination of the complete family (father and two other brothers) was performed thereafter. The father did not show any signs of a cardiac disease, the 13-year-old asymptomatic brother showed signs of discrete hypertrophy of the left ventricle, whereas the 10-year-old brother was clinically and morphologically unaffected. The pedigree of the investigated family is depicted in Fig. 1. Because of the severe disease of unknown origin, the 2-year-old boy underwent genetic testing by conventional sequencing of the most frequently affected disease gene of HCM, MYBPC3 (encoding cardiac myosin binding protein C). Two mutations were found in the boy (II/3 in Fig. 1)