Saha N, Tay J S, Humphries S E
Department of Paediatrics, Faculty of Medicine, National University of Singapore.
Genet Epidemiol. 1992;9(1):1-10. doi: 10.1002/gepi.1370090103.
The frequency of restriction fragment length polymorphisms (RFLPs) of the apolipoprotein B (apo B) gene, detected by XbaI and EcoRI, and their influence on serum lipids and apolipoproteins were studied in healthy Chinese of both sexes in Singapore. A total of 221 subjects (150 males, 71 females) were investigated for the XbaI and 159 subjects for the EcoRI polymorphisms, while serum lipids and apolipoprotein levels were available for 196 subjects. The frequency of the X2 allele was found to be significantly lower in the Chinese than that reported in Caucasians from the United Kingdom (0.09 vs. 0.51, P less than 0.001). The haplotype frequencies were also significantly different between the Chinese and Caucasians with a higher frequency of X1R1 in the former compared to the latter (0.85 vs. 0.34, P less than 0.0001). The distribution of RFLP genotypes at both of the restriction sites was at Hardy-Weinberg equilibrium in all groups. The influence of the apo B RFLPs on serum lipids and apolipoprotein levels (apo AI, AII, and B) was studied by both residual and multiple regression analyses considering age, sex, body mass index (BMI), and genotypes as independent variables in all possible combinations. No association was observed between the apo B genotypes and serum lipids or apolipoprotein levels except for high density lipoprotein cholesterol (HDLC), apo AI and AII, with the X2 being associated with significantly lower levels of HDLC as well as apo AI and AII, the effect being stronger in males. These data raise the possibility that the mechanism of reported association between apo B polymorphism and coronary artery disease may be through effects on HDLC.
在新加坡的华裔健康人群中，研究了用XbaI和EcoRI检测的载脂蛋白B（apo B）基因限制性片段长度多态性（RFLP）的频率及其对血脂和载脂蛋白的影响。共对221名受试者（150名男性，71名女性）进行了XbaI多态性研究，对159名受试者进行了EcoRI多态性研究，同时有196名受试者的血脂和载脂蛋白水平数据。发现华裔人群中X2等位基因的频率显著低于英国白种人报道的频率（0.09对0.51，P<0.001）。华裔和白种人的单倍型频率也有显著差异，前者X1R1的频率高于后者（0.85对0.34，P<0.0001）。所有组中两个限制性位点的RFLP基因型分布均处于Hardy-Weinberg平衡。以年龄、性别、体重指数（BMI）和基因型作为所有可能组合中的自变量，通过残差分析和多元回归分析研究了apo B RFLP对血脂和载脂蛋白水平（apo AI、AII和B）的影响。除高密度脂蛋白胆固醇（HDLC）、apo AI和AII外，未观察到apo B基因型与血脂或载脂蛋白水平之间存在关联，X2与HDLC以及apo AI和AII的水平显著降低有关，这种影响在男性中更强。这些数据提示，apo B多态性与冠状动脉疾病之间报道的关联机制可能是通过对HDLC的影响。
