[Mutation and clinical relevance in a large cohort of unrelated Chinese patients with hypertrophic cardiomyopathy].

OBJECTIVE: To explore the genetic basis and phenotypic correlation with disease severity in a large cohort of Chinese patients with hypertrophic cardiomyopathy (HCM). METHODS: A total of 179 unrelated Chinese HCM patients admitted to our department from 2002 to 2011 were enrolled in this study. Direct gene sequencing of ß-myosin heavy chain (MYH7), myosin binding protein-C ( MYBPC3), and cardiac troponin T (TNNT2) were performed and clinical data were obtained in these patients. RESULTS: A total of 34 mutations were identified in 40 patients (22.3%), 79.4% (27/34) mutations occurred only once and a possible hot spot, A26 in MYH7, was found. Distribution of mutations was 52.9% (18/34) (MYBPC3), 35.3% (12/34) ( MYH7) and 11.8% (4/34) (TNNT2) respectively. Double mutations were identified in 2.2% (4/179) patients. Genotype-positive patients were associated with an earlier symptom onset, severer left ventricular hypertrophy, a higher incidence of syncope, and were more likely to have positive family history of HCM or sudden cardiac death (SCD) , and were more likely to progress into heart failure (24.2% vs. 5.0%, P = 0.002) and at a higher risk of SCD (9.1% vs. 0, P = 0.009) during the 6.5-year follow-up. No statistical difference in any clinical parameters and outcomes was found between patients carrying MYBPC3 and MYH7 mutations. Double mutations were associated with malignant clinical progression in this cohort. Different phenotype severity could be seen in HCM patients with same genotype (e. g. MYH7-1736T, TNNT2-R92W). CONCLUSION: MYBPC3 is the most predominant gene mutation in this HCM cohort. The presence of a sarcomere mutation in patients with HCM is associated with poor clinical outcome, although no specific genes or mutations can exactly predict the severity of clinical phenotypes.

Application of transgenic animal in hypertrophic cardiomyopathy / 北京大学学报(医学版)

Hypertrophic cardiomyopathy is an autosomal-dominant disease.Disease-causing mutations have been found in genes encoding structural components of the thick and thin filament systems of cardiac myocyte;it has therefore been named as a disease of sarcomere.Many approaches have been used to characterize the pathogenesis of the desease.Transgenic animal models have been created to gain further insight into the pathogenesis of this disease.Most of these models has been made in mice;however,recently a transgenic rabbit model has been created.In addition,there are several natural-occurring forms of HCM in animals.The discovery of responsible genes and the elucidation of the molecular mechanisms of pathogenesis through the use of animal models promise improved and early diagnosis and the potential for mechanism-based therapeutics.