Association between fibrillin-1 gene exon 15 and 27 polymorphisms and risk of mitral valve prolapse.

BACKGROUND AND AIM OF THE STUDY: Fibrillin is one of the structural components of the elastin-associated microfibrils found in the mitral valve. Abnormalities of elastic fiber were found in floppy mitral valves. The role of fibrillin genetic variant in isolated mitral valve prolapse (MVP) has not been studied. Hence, a case-controlled study was performed to investigate the relationship between fibrillin-1 gene polymorphisms and risk of MVP in Taiwan Chinese.

METHODS: One hundred patients with MVP diagnosed by echocardiography and 140 age- and sex-matched normal controls were studied. Polymorphisms of exon 15, 27 and intron C of the fibrillin-1 gene (FBN1) were identified by polymerase chain reaction-based restriction analysis.

RESULTS: A significant difference was seen in genotype distribution or allelic frequency between MVP cases and controls for either FBN1 exon 15 polymorphism (p = 0.012 and 0.002, respectively) or exon 27 polymorphism (p = 0.04 and 0.02, respectively). Odds ratios (OR) for risk of MVP associated with FBN1 exon 15 TT and exon 27 GG genotypes were 2.40 (95% CI 1.32-4.39) and 3.61 (95% CI 1.01-12.89), respectively. OR for risk of MVP associated with FBN1 exon 15 T and exon 27 G alleles were 2.24 (95% CI 1.32-3.81) and 1.66 (95% CI 1.07-2.56), respectively. There was no significant difference in the distribution of FBN1 intron C genotypes (p = 0.58) and allelic frequency (p = 0.34) between MVP cases and controls.

CONCLUSION: Patients with MVP have higher frequencies of FBN1 exon 15 TT and exon 27 GG genotypes, which supports a role of the FBN1 exon 15 and 27 polymorphisms in determining the risk of MVP among the Chinese population in Taiwan.