[Polymorphisms of the Arsenite Methyltransferase (As3MT) gene and urinary efficiency of arsenic metabolism in a population in northern Mexico].

The aim of this study was to assess the relationship of the rs11191439 and rs3740393 polymorphisms of the Arsenite Methyltransferase (As3MT) gene with the arsenic urinary excretion profiles in a population in northern Mexico. A crosssectional study was conducted with 102 participants between the ages of 14 and 75 in Comarca Lagunera, Mexico. Speciation of the arsenic urinary metabolites was determined, and DNA was extracted; analysis and amplification of the polymorphisms was made by PCR in real time. A descriptive analysis was carried out and the differences in the urinary arsenic concentrations were assessed according to sex and genotype. The median concentration of arsenic in water was 82 μg/L; the levels of urinary excretion of dimethylarsinic acid (DMA) were higher in women than in the men. The carriers of the CC genetic variant of the As3MT (rs3740393) gene showed higher urinary concentrations of methylarsinic acid (p=0.01) and DMA (p=0.05).