Abstract
Serum paraoxonase (PON1) and hemochromatosis (HFE) genes may play important roles in lead toxicity owing to their role in xenobiotic and iron metabolism, respectively. The association between PON1 and HFE genotypes and blood lead levels (BLLs) was examined in lead exposed subjects from Saudi Arabia. The polymorphisms at PON1 L55M, PON1 Q192R, HFE H63D and HFE C282Y (using PCR-RFLP) and their relation to BLLs was evaluated. The recruited subjects (N = 127) were categorized into low BLL group (<10 mu g/dL) and high BLL group (>10 mu g/dL) according to CDC guidelines. The low BLL group had a mean level of 3.94 mu g/dL, while the high BLL group had levels of 15.33 mu g/dL (P < 0.001). Overall, the genetic variants, TA and AA in the PON1 L55M were significantly (P = 0.00002 and P = 0.00322, respectively) associated with a risk of lead toxicity and the allele 'A' was a risk factor (P = 0.00002). However, the Q192R genotype of PON1 along with HFE H63D and HFE C282Y did not significantly increase the risk of developing lead poisoning. Our findings suggest that L55M gene polymorphism influences the susceptibility of subjects to lead exposure and thus it could be a useful biomarker of genetic susceptibility in assessing an individual's risk of damage from heavy metal exposure.