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

ObjectiveThe aim of this study is to investigate if an association exists between single nucleotide polymorphism (SNP) in the tumor necrosis factor-alpha (TNF-α) and TNF-β genes.MethodsThe DNA was extracted and SNP in the human TNF-α and TNF-β 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-α in different stages of pregnancy were quantified using enzyme linked immunosorbent assay (ELISA).ResultsThere was no significant difference in genotype and allele frequency of SNP at position −308 (G/A) in the promoter region of the human TNF-α gene as well as the SNP at position 252 (A/G) in the human TNF-β gene between the GDM and control subjects. Using the logistic regression model, it was found that the SNP in the TNF-α as well as TNF-β were not associated with development of GDM. In addition, the TNF-α levels in the plasma of GDM and control mothers were not significantly different.ConclusionsIn the population studied, the SNP in position −308 (G/A) of the human TNF-α or in position 252 (A/G) of the human TNF-β gene is not an independent risk factor or a predictor for GDM.