[Malignant hypertrophic cardiomyopathy caused by the Arg723Gly mutation in beta-myosin heavy chain gene in a Chinese pedigree]

Hypertrophic cardiomyopathy (HCM) is a genetically and phenotypically heterogeneous disease and an Arg723Gly mutation in beta-myosin heavy chain (beta-MHC) gene was found in 3 Spanish families with malignant HCM. We detected this gene mutation in 5 Chinese pedigrees with hypertensive cardiomyopathy.Five Chinese pedigrees with HCM and 80 age-matched normal control subjects were chosen for the study. The exons in the functional regions of the beta-MHC gene were amplified with PCR and the products were sequenced, genotype and phenotype analyzed.Arg723Gly mutation was identified in exon 20 in one pedigree. In this pedigree, 13 out of 25 family members were diagnosed as HCM, 5 died of heart failure, all HCM patients in this pedigree had Arg723Gly mutation and 3 of them had NYHA III and 2 of them were diagnosed as HCM before the age of 20.Arg723Gly mutation was also one of the main disease-causing genes in Chinese familial HCM. The mutation of Arg723Gly is a malignant phenotype as shown by early progressive heart failure development and poor prognosis in this pedigree with Arg723Gly mutation.