Objective: To evaluate the influence of the angiotensinogen(AGT) gene M235T variant on the prevalence and severity of hypertrophic cardiomyopathy(HCM).
Methods: The authors conducted a case-control study on 152 subjects, including 72 HCM patients and 80 normal controls. Polymerase chain reaction(PCR) combined with restriction fragment length polymorphism(RFLP) was used to detect the M235T variant of AGT gene. Interventricular septum thickness, left ventricular posterior wall thickness and apical wall thickness were measured by means of M-mode echocardiography under two-dimensional guidance in the parasternal long-axis plane and apical two- and four-chamber views.
Results: (1) The genotype distributions of AGT gene in both groups were in agreement with Hardy-Weinberg equilibrium. (2) The genotype distributions of the M235T variant differed significantly in HCM patients and controls(chi-square=6.090 P<0.05). The frequencies of TT genotype and T235 allele in HCM patients were higher than did the patients in controls(TT genotype 0.63 vs 0.45 OR=2.037 95%CI 1.064-7.899 P<0.05 T235 allele 0.78 vs 0.64 OR=1.990 95%CI 1.197-3.308 P<0.01). (3)The patients with the TT genotype had significantly greater mean left ventricular maximal wall thickness than did the patients with the MM and MT genotypes [(19.1+/-4.8) mm vs(15.3+/-2.6)mm and(16.2+/-5.1)mm F=4.261 P<0.05].
Conclusion: The variant M235T of the AGT gene is significantly associated with HCM in this population. The genotype TT or allele T might be a genetic risk factor for the development and extent of hypertrophy in HCM patients.