[Association and linkage analysis between the S447X polymorphism of LPL gene and serum lipids, blood pressures in twins].

OBJECTIVE

To investigate the association and linkage between the S447X polymorphism of LPL gene and serum lipids, blood pressures in the general population-based twin cohort of China.

METHODS

The twin subjects were collected based on the twin registry system of China. All twins were investigated by a standard questionnaire and physical examinations. PCR-RFLP method was used to detect the genotypes of S447X. Stratified by gender, the associations of S447X polymorphism with the serum lipids (TG, HDL), blood pressures (SBP, DBP) and their abnormalities were analyzed by univariate and multivariate methods. The Halesman-Elston regression based nonjparameter linkage analysis was applied in the DZ twins.

RESULTS

A total of 962 adult twin pairs were analyzed and the frequency of 447X allele was 8.6%. The heritabilities of TG, HDL, SBP and DBP were 57%, 68%, 46% and 44%, respectively. In female twins, univariate and multivariate association analyses showed that the 447X allele was associated with the 12.9% decrease of TG and 2.7 mm Hg (1 mm Hg=0.133 kPa) decrease of SBP, 1.8 mm Hg decrease of DBP. Also in female twins, 447X allele was associated with the lower risks of high TG dyslipidaemia, low HDL dyslipidaemia and hypertension, with the odds ratios 0.38 (95%CI: 0.20-0.76), 0.49 (95%CI: 0.29-0.81) and 0.47(95%CI: 0.25-0.86), respectively.

CONCLUSION

This study showed significant associations between the S447X polymorphism of LPL gene and the improved serum lipids, decreased blood pressures in the female twins. But no associations were observed in male twins, and no linkage evidences were found between the locus site of S447X polymorphism and the trait loci of serum lipids, blood pressures. So the associations maybe caused by the other functional SNPs within or near LPL gene, which might be in significant linkage disequilibrium with 447X mutation.