Genetics and Molecular Biology (Dec 2005)

Analysis of genetic susceptibility to mercury contamination evaluated through molecular biomarkers in at-risk Amazon Amerindian populations

  • Maria de Nazare Klautau-Guimarães,
  • Renata D’Ascenção,
  • Fabiana A. Caldart,
  • Cesar K. Grisolia,
  • Jurandir R. de Souza,
  • Antonio C. Barbosa,
  • Célia M.T. Cordeiro,
  • Iris Ferrari

DOI
https://doi.org/10.1590/S1415-47572005000500027
Journal volume & issue
Vol. 28, no. 4
pp. 827 – 832

Abstract

Read online

We investigated Individual differences in susceptibility to methylmercury (MeHg) contamination and its relationship with polymorphisms of the detoxifying enzyme glutathione S-transferase (GST). In Brazil, some Amerindian tribes from the Amazon region have an increased level of mercury in their hair. Samples of hair and blood were taken from inhabitants of two villages in the Kayabi and Munduruku Amerindian communities to investigate mercury levels in association with genetic polymorphism of GSTs. Other molecular biological markers were also studied, such as hemoglobin, haptoglobin and glucose 6-phosphate dehydrogenase (G-6-PDH). Higher levels of mercury contamination were found in the Kayabi villagers, who had a null genotype (GSTM1 0/0, also denominated GSTM1 null) frequency of 26%, than in the Munduruku villagers, for which the null genotype frequency was 0%. Individuals with the GSTM1 null phenotype had higher concentrations of mercury in their hair than individuals with GSTM1+/+ phenotypes (F = 21.51, p < 0.0001). No association with other markers studied was observed. This study suggests that GSTM1 may be involved in the biotransformation of mercury in humans.

Keywords