[DNA polymorphisms of apolipoprotein A I gene in Chinese endogenous hypertriglyceridemics]

The restriction fragment length polymorphisms (RFLPs) of apolipoprotein(apo) A I gene were studied using polymerase chain reaction (PCR) in 69 endogenous hypertriglyceridemics (HTG) and 74 healthy subjects from a population of Chinese Han nationality in Chengdu area. The loci studied included Msp 1 within intron 3 of the apo A I gene; Xmn I, 5' to the apo A I gene; and Pst I, 3' to the apo A I gene. The results showed that both in HTG group and control group M1, X1 and P1 alleles were the major alleles and homozyous M1M1, X1X1 and P1P1 genotypes were the most frequent ones. The frequencies of rare M2 and X2 alleles in Chinese were significantly higher than those in European Caucasians (0.293 vs 0.111, P < 0.0006, 0.286 vs 0.130, P < 0.004), but no differences were found in the frequency of rare P2 allele (0.071 vs 0.046, P > 0.05). The frequency of rare M2 tended to increase in the HTG group when compared with the control group (0.353 vs 0.275, P > 0.05). Both in the HTG group and control group, subjects with genotype M2M2 had a higher serum mean concentration of TC, apo C II and higher serum TG/HDL-C ratio compared with the subjects with the genotypes M1M1 and M1M2 (P = 0.05, P < 0.03, P < 0.04), and the serum TG, apo C II and apo E levels had a tendency to increase. The subjects with the genotypes P1P2 and P2P2 had a higher serum apo A II levels compared with the subjects with the genotype P1P1 (P < 0.04). The data show that the only Msp I RFLP within the intron 3 of apo A I gene is associated with endogenous hypertriglyceridemia to some extent in Chinese population.