Association between COL3A1 collagen gene exon 31 polymorphism and risk of floppy mitral valve/mitral valve prolapse.
BACKGROUND
Collagen structure is a key element in mitral valves. Collagen defects were proposed as the primary events causing floppy mitral valves (FMV). The role of collagen genetic variant in floppy mitral valve/mitral valve prolapse (FMV/MVP) has not been well studied. The purpose of this study is to investigate the possible relationship between the collagen gene polymorphisms and risk of FMV/MVP among the Chinese population in Taiwan.


METHODS
We studied 100 patients with FMV/MVP diagnosed by echocardiography and 243 age- and sex-matched normal control subjects. The polymorphisms of exon 31 and exon 52 of the collagen type III-alpha1 gene (COL3A1) were identified by polymerase chain reaction (PCR)-based restriction analysis.


RESULTS
There was a significant difference in either the genotype distribution (P<0.0001) or allelic frequencies (P<0.0001) between FMV/MVP cases and controls for COL3A1 exon 31 polymorphism. An odds ratio for risk of FMV/MVP associated with COL3A1 exon 31 GG genotype was 7.42 (95% confidence interval 4.40-12.52). An odds ratio for risk of FMV/MVP associated with COL3A1 exon 31 G allele was 2.28 (95% confidence interval 1.57-3.29). There was no significant difference in the distribution of COL3A1 exon 52 genotypes (P=0.31) and allelic frequencies (P=0.32) between FMV/MVP cases and controls. Further categorization of the FMV/MVP patients into mild and severe subgroups revealed no statistical difference from the controls for exon 31 or exon 52 polymorphism.


CONCLUSIONS
This study shows that patients with FMV/MVP have higher frequency of COL3A1 exon 31 GG genotype that supports a role of the COL3A1 exon 31 polymorphism in determining the risk of FMV/MVP among the Chinese population in Taiwan.
Chou
Hsiang-Tai
HT
Division of Cardiology, Department of Medicine, China Medical College Hospital, 2 Yuh Der Road, Taichung 404, Taiwan, ROC. chou.hsieh@msa.hinet.net
Hung
Jui-Sung
JS
Chen
Yng-Tay
YT
Wu
Jer-Yuarn
JY
Tsai
Fuu-Jen
FJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002681:China / Q000208:ethnology; D024061:Collagen Type III / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D008945:Mitral Valve Prolapse / Q000453:epidemiology / Q000235:genetics*; D011110:Polymorphism, Genetic; D012306:Risk; D013624:Taiwan / Q000453:epidemiology
C439971:COL3A1 protein, human; D024061:Collagen Type III