[Family Hypertrophic Cardiomyopathy Caused by a 14035c > T Mutation in Cardiac Troponin T Gene]

Objective: To study the disease-causing gene mutation in Chinese patients with familial hypertrophic cardiomyopathy (FHC) and to analyze the correlation between the genotype and the phenotype.

Methods: Peripheral blood samples were collected from 40 members from a family affected with FHC, and 120 healthy volunteers. PCR was performed to analyze the exons and flanking introns of the cardiac troponin T gene (TNNT2), beta-myosin heavy chain gene (MYH7), and myosin-binding protein C gene (MYBPC3) and the products were sequenced. The clinical data including symptom, physical examination, echocardiography and electrocardiography were collected.

Results: A 14035c > t mutation, which causes a missense mutation (R130C) in exon 10 of TNNT2 gene were identified in 4 family members, including the proband, female, aged 53, with the onset at the age of 30. The 4 persons with the 14035c > t mutation, all FHC patients, presented left ventricular dysfunction with a penetrance of 100%. Two of the patients died of sudden cardiac death during follow-up. No mutation was identified in the MYH7 and MYBPC3 genes.

Conclusion: The 14035c > t mutation of TNNT2 gene is the causal mutation of FHC which is associated with malignant phenotype with a penetrance of 100%. It is a reasonable procedure in HCM patients with malignant phenotype to screen mutation in the TNNT2 gene.