Genetic contribution of polymorphism of the GLUT1 and GLUT4 genes to the susceptibility to type 2 (non-insulin-dependent) diabetes mellitus in different populations.

Polymorphic variation of genes encoding the glucose transporters glycoproteins (GLUT) may contribute to the genetic susceptibility to type 2 (non-insulin-dependent) diabetes. In this study we evaluated the allele and genotype frequencies of GLUT1 and GLUT4 restriction fragment length polymorphism (RFLP), revealed by digestion with XbaI for GLUT1 and KpnI for GLUT4, in Caucasian, Chinese, Japanese, Asian Indian and American black populations. No differences of the KpnI GLUT 4 RFLP were found between control and diabetic subjects in any ethnic group or when all data are combined. In contrast, positive results were found for the XbaI RFLP: (1) most ethnic groups showed an association of allele 1 with type 2 diabetes, and this association was maintained when all groups were analysed together; (2) after stratifying for sex and obesity, this association was significant only for overweight/obese women. This joint analysis suggests that GLUT1 polymorphism may contribute to susceptibility to type 2 diabetes in some populations, and especially in overweight/obese women.