Distribution of glutathione S-transferase GSTM1 and GSTT1 null phenotypes in Brazilian Amerindians

Abstract

The distribution of glutathione S-transferase (GST) GSTM1 and GSTT1 null phenotype frequencies in two Brazilian Amerindian tribes, the Munduruku tribe from Missão Cururu village (79 individuals) and the Kayabi tribe (41 individuals), was analyzed by polymerase chain reaction (PCR) amplification. The GST null phenotype frequencies for the Munduruku sample were 0% for GSTM1 and 27% for GSTT1 while for the Kayabi sample the null phenotype frequencies were 27% for GSTM1 and 29% for GSTT1. This is the first report of the absence of the GSTM1 null phenotype in any ethnic group.

Evaluation of GlutathioneS-transferaseGSTM1andGSTT1Polymorphisms and Methylmercury Metabolism in an Exposed Amazon Population

“…Our data corroborate the findings of Lee et al (2010), who evaluated 417 North Korean pregnant women exposed to MeHg via consumption of contaminated fish and demonstrated that women with the GSTM1 * 0 and GSTT1 * 0 polymorphisms presented higher Hg concentrations in both maternal blood and in umbilical cord blood of respective newborns. Klautau-Guimarães et al (2005) studied an Amazon Amerindian population and found the same correlation with individuals who carry null genotypes of GSTM1 presenting higher B-Hg concentrations than those who carry the wild genotype. Therefore, data suggest that genetic factors may be used as an indicator of effect on Hg metabolism.…”

The importance of understanding the distribution of GSTM1 and GSTT1 genotypes and haplotypes in a region with intense agriculture activity

“…We observed that the city of Goiania has a different distribution of GSTM 1 and GSTT1 frequencies (p < 0.01) regarding all the municipalities and the other groups and countries (Table 4). Goiania is only like the populations of Riacho de Sucutiaba (Bahia, Brazil) (Hiragi et al., 2007) (p = 0.891) and Kayabu (Mato Grosso, Brazil) (Klautau-Guimarães et al., 2005) (p = 0.103) (Table 5). Considering the distribution of the null GSTM1 genotype, the other municipalities of our study do not present a significant difference from the Kalunga population and the Federal District, except Goiania.…”

“…In the Northeast of India, some authors (Thoudam et al., 2010) demonstrated a frequency of 32.7% for null GSTT1 and 41.9% for the null GSTM1 genotype. Klautau-Guimarães et al. (2005) evaluated 120 individuals, distributed in two Amerindian tribes of Brazil, the Munduruku tribe of the village of Missão Cururu, and the tribe of Kayabi.…”

Haptoglobin gene subtypes in three Brazilian population groups of different ethnicities

“…The Kayabi population had Hp genotype frequencies that were not in Hardy-Weinberg equilibrium, with an excess of heterozygotes (F IS = -0.5876). Factors that could account for this finding include the following: (i) the Kayabi live in an area that has experienced intense migration as a result of gold prospecting, and they have consequently become somewhat mixed ( Klautau-Guimarães et al , 2005b ), (ii) the Hp phenotypes are associated with several disorders such as diabetes and cardiovascular and infectious diseases ( Langlois and Delanghe, 1996 ; Sadrzadeh and Bozorgmehr, 2004 ; Carter and Worwood, 2007 ) that may have subjected the population to some form of natural selection and (iii) the Kayabi population consumes freshwater fish contaminated by monomethyl mercury, and is also exposed to endemic infectious diseases such as malaria, for which they lack basic medical services ( Dórea et al , 2005 , Klautau-Guimarães et al , 2005a ); the latter two hypotheses suggest selection in favor of heterozygotes.…”

“…1) The Kayabi are a Tupi-Guarani Amerindian tribe ( Rodrigues, 1994 ) with a population of about 1,000 found mainly in the Xingu Indigenous National Park (Mato Grosso state). The Kayabi village sampled consisted of 110 individuals living on the margins of the Teles Pires River (11° 37' 0" S and 55° 40' 60' W) ( Dórea et al , 2005 ; Klautau-Guimarães et al , 2005a , b ). More details about this tribe can be found in Dórea et al (2005) .…”