Association between angiotensin I-converting enzyme gene insertion/deletion polymorphism and mitral valve prolapse syndrome.

BACKGROUND: Some studies have reported that patients with mitral valve prolapse syndrome (MVPS) also have a disorder in the autonomic or neuroendocrine function, which can cause a host of related symptoms. A potential role of the renin-angiotensin system in the pathogenesis of MVPS has been addressed. However, the role of angiotensin I-converting enzyme (ACE) genetic variant in MVPS has not been studied. We therefore performed a case-control study investigating the possible relation between ACE gene polymorphisms and MVPS in Taiwan Chinese.

METHODS: We studied 100 patients with MVPS diagnosed by echocardiography and 100 age- and sex-matched normal control patients. ACE gene insertion/deletion (I/D), A-240T, and G2350A polymorphisms were identified by polymerase chain reaction-based restriction analysis.

RESULTS: There was a significant difference in the distribution of ACE I/D genotypes (P =.003) and allelic frequencies (P =.001) between MVPS cases and control patients. An odds ratio for the risk of MVPS associated with the ACE II genotype was 2.14 (95% CI 1.20-3.80 ). An odds ratio for the risk of MVPS associated with ACE I allele was 1.96 (95% CI 1.30-2.97). The A-240T and G2350A polymorphisms of the ACE gene showed no association with MVPS (P =.20, P =.13, respectively).

CONCLUSIONS: This study showed that patients with MVPS have a higher frequency of ACE II genotype, which supports a role of the ACE I/D gene polymorphism in determining the risk of MVPS among the Chinese population in Taiwan.