This research was funded by the vice presidency of environment, care and health promotion (VPAAS) of Fundação Oswaldo Cruz through the Decentralized Execution of Resources Document No. 175/2018, Process: 25000.209221/2018-18, signed between the Fundação Oswaldo Cruz and the Special Department for Indigenous Health, both under the Ministry of Health. This study was supported by the Brazilian agency Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro—FAPERJ and by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).State University of Rio de Janeiro - West Zone. Research Laboratory of Pharmaceutical Sciences. Rio de Janeiro, RJ, Brazil / Oswald Cruz Foundation. National School of Public Health. Program of Post-Graduation in Public Health and Environment. Rio de Janeiro, RJ, Brazil.University of São Paulo. Faculty of Medicine. São Paulo, SP, Brazil.Oswald Cruz Foundation. Polytechnic School of Health Joaquim Venâcio. Laboratory of Professional Education in Health Surveillance. Rio de Janeiro, RJ, Brazil.University of São Paulo. Faculty of Medicine. São Paulo, SP, Brazil.University of São Paulo. Faculty of Medicine. São Paulo, SP, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.State University of Rio de Janeiro - West Zone. Research Laboratory of Pharmaceutical Sciences. Rio de Janeiro, RJ, Brazil.Oswald Cruz Foundation. Polytechnic School of Health Joaquim Venâcio. Department of Endemic Diseases Samuel Pessoa. Rio de Janeiro, RJ, Brazil.Oswald Cruz Foundation. Polytechnic School of Health Joaquim Venâcio. Program of Post-Graduation in Public Health and Environment. Rio de Janeiro, RJ, Brazil / Oswald Cruz Foundation. Polytechnic School of Health Joaquim Venâcio. Department of Endemic Diseases Samuel Pessoa. Rio de Janeiro, RJ, Brazil.State University of Rio de Janeiro - West Zone. Research Laboratory of Pharmaceutical Sciences. Rio de Janeiro, RJ, Brazil.Genetic polymorphisms may be involved with mercury levels and signs and symptoms of intoxication from this exposure. Therefore, the aims were to describe the frequency of the GSTP1 polymorphism and to evaluate its effects on mercury levels and neurological signs in three Munduruku indigenous villages in the Brazilian Amazon. One-hundred-and-seven indigenous (over 12 years old) were included and genotyped (rs1695) using a TaqMan validated assay. Then, associations were evaluated by binary logistic regression, using odds ratios (OR) and 95% confidence intervals (CI). Mean age was 27.4 ± 13.9 years old, 52.3% were male, mean hair mercury concentration was 8.5 ± 4.3, exceeding the reference limit (≥6.0 µg/g), and were different among the three villages: 13.5 ± 4.6 µg/g in Sawré Aboy, 7.4 ± 2.3 µg/g in Poxo Muybu and 6.9 ± 3.5 µg/g in Sawré Muybu. The minor allele frequency of GSTP1 G was significantly different among the villages: 57% Sawré Muybu, 21% Poxo Muybu and 15% Sawré Aboy. Finally, after adjustment, GSTP1 GG and GA genotypes were associated with lower levels of Hg (OR = 0.13; CI95% = 0.03–0.49) and abnormal somatosensory signs (OR = 3.7; 95%IC = 1.5–9.3), respectively. In conclusion, monitoring this population is imperative to identify individuals at higher risk of developing signs of chronic mercury exposure based on the genetic profile
