Frequency distribution of XbaIG > T and HaeIIIT > C GLUT1 polymorphisms among different Brazilian ethnic groups G. C. S. Costa Æ L. C. J. Alcantara Æ R. Azevedo Æ G. Muricy Æ S. H. Kashima Æ D. T. Covas Æ B. Galva ˜o-Castro Æ S. R. Gadelha Received: 11 November 2008 / Accepted: 20 March 2009 / Published online: 4 April 2009 Ó Springer Science+Business Media B.V. 2009 Abstract GLUT is the major glucose transporter in mammalian cells. Single nucleotide polymorphisms (SNP) at GLUT1 promoter and regulatory regions have been associated to the risk of developing nephropathy in dif- ferent type 1 and type 2 diabetic populations. It has been demonstrated that differences in allelic and genotypic fre- quencies of GLUT1 gene (SLC2A1) polymorphisms occur among different populations. Therefore, ethnic differences in distribution of GLUT1 gene polymorphisms may be an important factor in determining gene-disease associa- tion. In this study, we investigated the XbaIG [ T and HaeIIIT [ C polymorphisms in six different Brazilian populations: 102 individuals from Salvador population (Northern Brazil), 56 European descendants from Joinville (South Brazil), 85 Indians from Tiryio ´ tribe (North Brazil) and 127 samples from Southern Brazil: 44 from European descendants, 42 from African descendants and 41 from Japanese descendants. Genotype frequencies from both sites did not differ significantly from those expected under the Hardy–Weinberg equilibrium. We verified that the allele frequencies of both polymorphisms were heteroge- neous in these six Brazilian ethnic groups. Keywords GLUT1 Á Polymorphisms Á Brazilian populations Introduction Mammalian cells usually require blood glucose as their major source of energy and this molecule is transported into the cell by the glucose transporters (GLUT). These transporters constitute a family of 13 members which facilitate basal glucose transport into cells. GLUT1, a member of the class I family of glucose transporters together with GLUT2, GLUT3, GLUT4 and GLUT14, is a uniport carrier that passively facilitates glucose transport across membranes. GLUT1 is widely expressed as it is the main glucose transporter in the brain, placenta and eryth- rocytes [1]. The GLUT1 gene is located on chromosome 1 at 1p31–35.2 and single nucleotide polymorphisms (SNP) in its promoter (-2841 A [ T) and regulatory (XbaIG [ T, HaeII Enhancer-2 SNP1) regions have been implicated in the risk of developing nephropathy in different type 1 and type 2 diabetic populations [2–7]. In addition, it has been previously demonstrated that differences in allelic and genotypic frequencies of GLUT1 gene polymorphisms occur among different populations [2–7], for example, the XbaIG [ T polymorphism shows a frequency of the G allele of 55.0% in African–American population and of 79.0% in Chinese population [5, 8]. This ethnic diversity G. C. S. Costa Á L. C. J. Alcantara Á G. Muricy Á B. Galva ˜o-Castro Á S. R. Gadelha Laborato ´rio Avanc ¸ado de Sau ´de Pu ´blica, Centro de Pesquisas Gonc ¸alo Moniz, Fundac ¸a ˜o Oswaldo Cruz, Salvador, Bahia, Brazil L. C. J. Alcantara Á G. Muricy Á B. Galva ˜o-Castro Á S. R. Gadelha Escola Bahiana de Medicina e Sau ´de Pu ´blica, Salvador, Bahia, Brazil R. Azevedo Á S. H. Kashima Á D. T. Covas Laborato ´rio de Biologia Molecular, Banco de Sangue Regional de Ribeira ˜o Preto, Faculdade de Medicina de Ribeira ˜o Preto, Universidade de Sa ˜o Paulo, Sa ˜o Paulo, Brazil S. R. Gadelha (&) Universidade Estadual de Santa Cruz, Campus Prof Soane Nazare ´ de Andrade, Km 16—Rodovia Ilhe ´us/Itabuna, Ilheu ´s, Bahia 45650-000, Brazil e-mail: srgmello@uesc.br 123 Mol Biol Rep (2010) 37:75–79 DOI 10.1007/s11033-009-9528-0