Ethnicity and glutathione S-transferase (GSTM1/GSTT1) polymorphisms in a Brazilian population

Abstract

The distribution of polymorphisms related to glutathione S-transferases (GST) has been described in different populations, mainly for white individuals. We evaluated the distribution of GST mu (GSTM1) and theta (GSTT1) genotypes in 594 individuals, by multiplex PCRbased methods, using amplification of the exon 7 of CYP1A1 gene as an internal control. In São Paulo, 233 whites, 87 mulattos, and 137 blacks, all healthy blood-donor volunteers, were tested. In Bahia, where black and mulatto populations are more numerous, 137 subjects were evaluated. The frequency of the GSTM1 null genotype was significantly higher among whites (55.4%) than among mulattos (41.4%; P = 0.03) and blacks (32.8%; P < 0.0001) from São Paulo, or Bahian subjects in general (35.7%; P = 0.0003). There was no statistically different distribution among any non-white groups. The distribution of GSTT1 null genotype among groups did not differ significantly. The agreement between self-reported and interviewer classification of skin color in the Bahian group was low. The interviewer classification indicated a gradient of distribution of the GSTM1 null genotype from whites (55.6%) to light mulattos (40.4%), dark mulattos (32.0%) and blacks (28.6%). However, any information about race or ethnicity should be considered with caution regarding the bias introduced by different data collection techniques, specially in countries where racial admixture is intense, and ethnic definition boundaries are loose. Because homozygous deletions of GST gene might be associated with cancer risk, a better understanding of chemical metabolizing gene distribution can contribute to risk assessment of humans exposed to environmental carcinogens.

Increased Risk of Acute Myeloid Leukemia in Patients with &lt;i&gt;CYP&lt;/i&gt;1&lt;i&gt;A&lt;/i&gt;1 Polymorphisms

“…The patients studied might have another genotype ancestry different from our data and the number of subjects was relatively small (n = 38). We also confirmed the pattern of cytogenetic abnormalities distribution was similar to larger series of patients and previously published in Brazil and elsewhere [8,9,14,15,[17][18][19].…”

“…There are no other studies reporting CYP1A1 * 3 frequency in AML patients [3][4][5][6][7][14][15][16][17][18]. Thus, by the multivariate analysis our data showed that CYP1A1 * 3 increases the risk of AML 4-fold.…”

“…Polymorphisms were categorized as wild-type, heterozygous or mutant. del{GSTM1} and del{GSTT1} were studied using a PCR technique using a well standardized technique [14,15]. Beta-globin gene was amplified as an internal control.…”

CYP1A1, GSTM1, GSTT1 and GSTP1 polymorphisms in an Afro-Brazilian group

“…The GSTM1 and GSTT1 null genotype frequencies for our Porto Alegre Afro-Brazilian sample were similar to those described for other Afro-Brazilian populations Rossini et al, 2002;Gattás et al, 2004) which themselves are similar to the frequencies described for other (non-Brazilian) Afro-descend populations (Harries et al, 1991, Bailey et al, 1998. These studies have also detected significant differences in the frequency of GSTM1 polymorphisms among Afro-Brazilians and Brazilians of European descent Rossini et al, 2002;Gattás et al, 2004).…”

Interação entre consumo alimentar e polimorfismos da GSTM1 e GSTT1 no risco para o câncer de cabeça e pescoço: estudo caso-controle em São Paulo, Brasil

“…Os dados da literatura são escassos em relação à contribuição de variáveis genéticas e a dieta no risco de câncer de cabeça e pescoço. É interessante ressaltar que variáveis específicas em nossa população podem contribuir para os resultados observados, como a frequência desses polimorfismos em diferentes grupos populacionais do Brasil 23 . Por outro lado, mesmo a alimentação pode ser extremamente variável em decorrência de fatores ambientais e culturais.…”