Angiotensin II type 1 receptor gene polymorphism and mitral valve prolapsesyndrome

Background Mitral valve prolapse syndrome (MVPS), a term applied to patient s who have a variety of symptoms, has been associated with autonomic or neu roendocrine dysfunction. Recent evidence suggests that effects of angiotens in II mediated by the angiotensin II type 1 (AT(1)) receptor are involved i n modulation of cardiovascular autonomic control in human beings. Associati on of a genetic polymorphism (A-C-1166) of the AT(1) gene with abnormal vas omotion and low blood pressure related to autonomic control has been report ed recently. Because the role of this genetic variant in MVPS has not been studied, we performed a case-control study of the A-C-1166 variant in a gro up of 76 white subjects with MVPS. Methods and Results All patients were genotyped by use of a mismatch polyme rase chain reaction/Afl II restriction fragment length polymorphism analysi s. Frequency of the C-1166 allele was 0.4 in patients with MVPS and 0.26 in control patients. The difference in genotype (chi square = 6.5; P < .05) a nd allele (chi square = 5.9; P = .02) frequencies between the groups was si gnificant. The odds ratio in favor of carrying the C allele was 4 times gre ater for patients with MVP than for control patients (95% confidence interv al 1.4 to 12.1). Conclusions The current results indicate that the A-C-1166 polymorphism of the angiotensin It type 1 receptor gene is associated with MVPS in the whit e population.