Influence of vitamin D receptor haplotypes on blood lead concentrations in environmentally exposed children of Uygur and Han populations.

Objective: To explore the association between polymorphism of vitamin D receptor (VDR) and lead poisoning in Uygur and Han children in China.

Methods: The BsmI, ApaI and TaqI restriction sites of VDR genotyping were determined by polymerase chain reaction-restriction fragment length polymorphism in 443 Uygur and 469 Han children from Xinjiang province. The correlation between the polymorphism of VDR haplotypes and blood lead levels was explored.

Results: The genotype frequencies of VDR had significant differences in Han and Uygur children (p <0.01). According to VDR-BsmI, ApaI and TaqI haplotype analysis in Han children, haplotypes Atb and AtB were considerably decreased in the lead poisoning group (p <0.05) while haplotype aTb and ATb were significantly increased in the lead poisoning group (p <0.01). However, such results were not found in Uygur children (p < 0.05).

Conclusion: A significant difference was seen in the frequency distribution of the VDR genotype among the different races. Haplotypes Atb and AtB might be protective factors while haplotypes ATb and aTb might be risk factors in Han children.