Lack of association of δ‐aminolevulinic acid dehydratase genotype with blood lead levels in environmentally exposed children of Uygur and Han populations

Aim: A cross-section study was conducted to explore the association between polymorphism of δ-aminolevulinic acid dehydratase (ALAD) and lead poisoning in Uygur and Han children in China. Methods: The ALAD genotyping was determined by PCR-RFLP in 443 Uygur and 469 Han children aged 6–10 years from Urumqi in Xinjiang province. Results: The blood lead levels of 912 environmentally exposed children ranged from 0.5 to 48.2 μg/dL, with a mean of 5.45 μg/dL and a standard deviation of 0.22 μg/dL, and 23. Thirty-one percent individuals were with blood lead level ≥10 μg/dL. The mean and standard deviation of blood lead levels were 5.57 ± 0.223 μg/dL and 5.30 ± 0.224 μg/dL in Uygur and Han children, respectively. The frequencies of the allele ALAD1 and ALAD2 in Uygur subjects were 90.52% and 9.48%, and in Han subjects were 95.73% and 4.27%, respectively (chi-square = 19.55, p < 0.05). No statistic correlation between the distribution of ALAD alleles and the blood lead level was found in both populations. Conclusion: A significant difference was seen in the frequency distribution of ALAD genotype between the different races. The genetic susceptibility of ALAD polymorphism to lead toxicity may exhibit in a lead dose-dependent manner.