Haplotype analysis of Apo AI-CIII-AIV gene cluster and lipids level: Tehran lipid and glucose study

Iranian populations show an increased tendency for abnormal lipid levels and high risk of Coronary artery disease. Considering the important role played by the ApoAI-CIII-AIV gene cluster in the regulation of the level and metabolism of lipids, this study aimed at elucidating the association between five single nucleotide polymorphisms on the Apo11q cluster gene and lipid levels. A cross-sectional study of 823 subjects (340 males and 483 females) from the Tehran lipid and glucose study (TLGS) was conducted. Levels of TG, Chol, HDL-C, Apo AI, Apo AIV, Apo B, and Apo CIII were measured, and the selected segments of the APOAI-CIII-AIV gene cluster were amplified by PCR and the polymorphisms were revealed by RFLP using restriction enzymes. The allele frequencies for each SNP between males and females were not significantly different. The distribution of Genotypes and alleles was in Hardy–Weinberg equilibrium except for Apo AI (+83C>T). The results showed a significant association between TG, HDL-C, HDL₂, Apo AI, and Apo B levels and the presence of some alleles in the polymorphisms studied. After haplotype analysis not only did the association between these variables and SNPs remain but also levels of Chol and LDL-C were added. This study demonstrates that the level of lipids such as TG, HDL-C, HDL₂, Apo AI, and Apo B, maybe regulated partly by genetic factors and their haplotype within the Apo11q gene cluster.