Mutation of Arg723Gly in beta-myosin heavy chain gene in five Chinese families with hypertrophic cardiomyopathy.
BACKGROUND
Hypertrophic cardiomyopathy (HCM) is a form of cardiomyopathy with an autosomal dominant inherited disease, which is caused by mutations in at least one of the sarcomeric protein genes. Mutations in the beta-myosin heavy chain (beta-MHC) are the most common cause of HCM. This study was to reveal the disease-causing gene mutations in Chinese population with HCM, and to analyze the correlation between the genotype and phenotype.


METHODS
The exons 3 to 26 of MYH7 were amplified by PCR, and the PCR products were sequenced in five non-kin HCM patients. A 17-year-old patient was detected to be an Arg723Gly mutation carrier. Then his family was gene-screened, and the correlation between genotype and phenotype was analyzed.


RESULTS
The mutation of Arg723Gly in a Chinese family with HCM was detected for the first time. With a C-G transversion in nucleotide 13,619 of the MYH7 gene, located at the essential light chain interacting region in S1, the replacement of arginine by glycine took place at amino acid residue 723. A two-dimensional echocardiogram showed moderate asymmetrical septal hypertrophy with left atria enlargement. There was no obstruction in the left ventricular outflow tract. In his family, a total of 13 individuals were diagnosed HCM and 5 of them were dead of congestive heart failure at a mean age of 66-year-old. Eight living members were all detected to carry the mutation, in which 3 developed progressive heart failure. Moreover, the heart function of the people evidently deteriorates when their age are older than 50. The mutation and the disease show co-separated.


CONCLUSIONS
The Arg723Gly mutation is a malignant type. In Chinese the mutation has the similar characters to the former report but has low degree malignant.
Yang
Jun-hua
JH
Department of Cardiology, First Affiliated Hospital of Soochow University, Suzhou 215006, China. yangjhsz@163.com
Zheng
Dong-dong
DD
Dong
Ning-zheng
NZ
Yang
Xiang-jun
XJ
Song
Jian-ping
JP
Jiang
Ting-bo
TB
Cheng
Xu-jie
XJ
Li
Hong-xia
HX
Zhou
Bing-yuan
BY
Zhao
Cai-ming
CM
Jiang
Wen-ping
WP
D000293:Adolescent; D000328:Adult; D024741:Cardiomyopathy, Hypertrophic, Familial / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D018995:Myosin Heavy Chains / Q000235:genetics*; D024723:Ventricular Myosins / Q000235:genetics*
D024723:Ventricular Myosins; D018995:Myosin Heavy Chains