OBJECTIVETo detect the disease-causing gene mutation of hypertrophic cardiomyopathy (HCM) in a Chinese family and to analyze the correlation of the genotype and the phenotype.

METHODSOne family affected with HCM was studied. The clinical data including symptom, physical examination, echocardiography and electrocardiography were collected. The full encoding exons and flanking sequences of beta-myosin heavy chain gene (MYH7) and cardiac myosin-binding protein C gene (MYBPC3) were amplified with PCR and the products were sequenced.

RESULTSA G8887A mutation, which is an acceptor splicing site of intron 15 (IVS15-1G > A) in MYBPC3 (gi: Y10129) was identified in 6 out of 11 family members. Three mutation carriers developed HCM at 48 - 75 years old with mild chest pain, chest distress and asymmetric septal hypertrophy (13 - 14 mm) and remaining mutation carriers are free of HCM. No mutation was identified in MYH7 gene.

CONCLUSIONHCM caused by the IVS15-1G > A mutation is a benign phenotype. It is helpful to screen MYBPC3 gene mutation in late-onset HCM patients with mild symptoms.