Association between polymorphisms in human tumor necrosis factor-alpha (-308) and -beta (252) genes and development of gestational diabetes mellitus

Objective: The aim of this study is to investigate if an association exists between single nucleotide polymorphism (SNP) in the tumor necrosis factor-alpha (TNF-alpha) and TNF-beta genes. Methods: The DNA was extracted and SNP in the human TNF-alpha and TNF-beta genes at positions -308 (G/A) and 252 (A/G), respectively, was analyzed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma levels of TNF-alpha in different stages of pregnancy were quantified using enzyme linked immunosorbent assay (ELISA). Results: There was no significant difference in genotype and allele frequency of SNP at position -308 (G/A) in the promoter region of the human TNF-alpha gene as well as the SNP at position 252 (A/G) in the human TNF-beta gene between the GDM and control subjects. Using the logistic regression model, it was found that the SNP in the TNF-alpha as well as TNF-beta were not associated with development of GDM. In addition, the TNF-alpha levels in the plasma of GDM and control mothers were not significantly different. Conclusions: In the population studied, the SNP in position -308 (G/A) of the human TNF-alpha or in position 252 (A/G) of the human TNF-beta gene is not an independent risk factor or a predictor for GDM. (C) 2010 Elsevier Ireland Ltd. All rights reserved.