Objective: To investigate the association between haplotypes of S447X and Hind III polymorphisms of lipoprotein lipase (LPL) gene and serum lipids in a population-based twin cohort study in China.
Methods: Twin subjects were collected based on the twin registry system of China. All twins were investigated by a standard questionnaire and physical examinations. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to detect the genotypes of S447X and Hind III polymorphisms. Linkage disequilibrium test and haplotypes were estimated between two polymorphisms.
Results: Nine hundred and eighty-seven pairs of twins were eligible for analysis. The two polymorphisms of LPL gene were significantly linkage disequilibrium. In female twins, the H- allele of Hind III polymorphism was significantly related to lower levels of triglycerides(TG) and lower risk of high TG dislipidemia, but those associations disappeared after adjusting the polymorphism of S447X. The H- X haplotype of those two polymorphisms was significantly related to lower TG and TG/HDL (decreasing 12.9% and 14.9% respectively), as well as significantly to lower risk of high TG dislipidemia (OR = 0.40).
Conclusion: The haplotypes of S447X and Hind III polymorphisms were significantly related to the favorable effect of lipids,but this effect was mostly determined by the polymorphism of S447X, while the effect of Hind III polymorphism was indirectly influenced by the linkage disequilibrium with S447X polymorphism.