Association of vitamin D receptor gene haplotypes and genotype combinations with susceptibility to occupational elevated blood lead / 中华劳动卫生职业病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the association of the haplotypes and genotype combinations of vitamin D receptor (VDR) BsmI (rs1544410), Tru9I (rs757343), ApaI (rs7975232), and TaqI (rs731236) with the susceptibility to elevated blood lead in Chinese Han population.</p><p><b>METHODS</b>According to Diagnostic Criteria of Occupational Chronic Lead Poisoning (GBZ 37-2002) and Occupational Exposure Limits for Hazardous Agents in the Workplace Part 1: Chemical Hazardous Agents (GBZ 2.1-2007), the workers were divided into high-exposure group (lead dust ≥ 0.05 mg/m(3), lead fume ≥ 0.03 mg/m(3)) and low-exposure group based on the concentrations of lead fume and lead dust in the workplace. The high-exposure group was further divided into normal-blood lead subgroup and high-blood lead subgroup. Fasting peripheral venous blood (5 ml) was collected using a heparin tube; genomic DNA was extracted from the peripheral blood cells with a Qiagen kit; single nucleotide polymorphisms were detected by allelic discrimination assay using TaqMan probes (carrying fluorescent dyes); haplotypes were analyzed and compared by Haploview.</p><p><b>RESULTS</b>VDR BsmI, Tru9I, ApaI, and TaqI were in Hardy-Weinberg equilibrium between the normal-blood lead subgroup and high-blood lead subgroup (P > 0.05). Compared with haplotype CCCA which had the highest distribution frequency, haplotypes CCAA and CTCA were the high-risk factors for elevated blood lead (OR = 1.814, 95%CI = 1.055 ∼ 3.119; OR = 1.919, 95%CI = 1.040 ∼ 3.540). Compared with genotype combination CC + CC + CC + AA which had the highest distribution frequency, genotype combination CC + CC + AC + AA was the high-risk factor for elevated blood lead (OR = 2.800, 95%CI = 1.282 ∼ 6.116).</p><p><b>CONCLUSION</b>As for VDR BsmI, Tru9I, ApaI, and TaqI, haplotypes CCAA and CTCA and genotype combination CC + CC + AC + AA are associated with the susceptibility to elevated blood lead.</p>