Relationship of subclasses of serum HDL and Apo A-Ⅰ gene polymorphism in hyperlipidemia

AIM: To investigate apolipoprotein A-Ⅰ gene (Apo A-Ⅰ) polymorphism and its relationship with serum HDL subclasses in patients with hyperlipidemia (HL). METHODS: Apo A-Ⅰ genotype was assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The subclasses of serum HDL in 118 patients with hyperlipidemia and 109 healthy subjects were determined by two-dimensional gel electrophoresis conjunction with immunodetection method. RESULTS: Both in HL group and the control group, G/G and C/C genotypes were the most frequent at －78 bp and ＋83 bp of Apo A-Ⅰ gene, respectively. The frequency of rare A allele at －78 bp in HL group was significantly higher than that in control group. In HL group, subjects with G/A mutation had higher serum levels of TG, Apo C-Ⅲ, pre β1-HDL and HDL3a, and lower levels of HDL2a and HDL2b compared to the subjects with G/G genotype. CONCLUSION: The G/A transition in the －78 bp position of the Apo A-Ⅰ gene promoter in patients with hyperlipidemia is associated with HDL subclasses. There is a general shift toward smaller sized HDL, which, in turn, indicates that HDL maturation might be abnormal.