Lack of association of delta-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 delta-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 microg/dL, with a mean of 5.45 microg/dL and a standard deviation of 0.22 microg/dL, and 23. Thirty-one percent individuals were with blood lead level > or =10 microg/dL. The mean and standard deviation of blood lead levels were 5.57 +/- 0.223 microg/dL and 5.30 +/- 0.224 microg/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.