Glutathione S-transferase (T1 & M1) Null Genotypes as Risk Determinants in Sudanese for Developing Type Two Diabetes Mellitus

Abstract

Glutathione S-transferases (GSTT1 and GSTM1) are globular proteins responsible for the detoxification of xenobiotics and the prevention of oxidative damage. Functional polymorphisms of the antioxidant glutathione and enzymes have a role in the pathogenicity of T2DM and its complications. The present study is aimed to assess association between GSTM1 and GSTT1 genetic polymorphisms with T2DM in Sudanese people. This case-control study was done in Khartoum. A total of 181 Sudanese (115 T2DM patients and 66 controls) included in this study. Genomic DNA was extracted and processed by Multiplex PCR. The present genotype and null genotypes of GSTT1 and GSTM1 were identified. The biochemical parameters have been estimated in plasma samples. Glycated hemoglobin was also estimated in the whole blood samples. SPSS version 20 was used for the analysis of genotypes distribution, mean values, P-values and Odd Ratio with 95% confidence intervals. Sudanese patients with T2DM showed an increased frequency of the GSTT1 null genotype when compared to the non-diabetic controls (48.7% versus 28.8%). The diabetic patients showed a lower frequency of GSTT1 genotype compared to their controls (51.3% versus 71.2%). The study revealed a high frequency of the GSTM1 null genotype in diabetic Sudanese compared to their controls (40.9% versus 36.4%); while type-2 diabetes mellitus patients showed a lower frequency of GSTM1 present genotype compared to non-diabetic Sudanese (59.1% versus 63.6%). The GSTM1 and GSTTI genes polymorphism can be a good marker for early identification of Sudanese people at risk of T2DM and its complications.