Cytokine gene polymorphism frequencies in Turkish population living in Marmara region

Objectives Sequence variants in cytokine genes are related to affect cytokine gene levels. In this study, it was aimed to examine eight single nucleotide polymorphisms (SNPs) in five cytokine genes (TNF-alpha, INF-gamma, IL-6, IL10, TGF-beta) for the Turkish population living in Marmara region and to reveal the genetic distance between the study group and other populations. Methods In this study, three-hundred unrelated healthy individuals were involved and all genotyping were performed by using sequence-specific primers PCR (PCR-SSP) method. The SNP data were analyzed for Hardy Weinberg equilibrium fit by calculating expected genotype frequencies and comparing them to the observed values using Arlequin software version 3.1. The genetic distances between the study group and other populations were calculated and a neighbor-joining tree was constructed by PHYLIP. Results The observed genotypes of TNF-alpha (-308), IFN-gamma (+874), TGF-beta (codon 10), and TGF-beta (codon 25) of the subjects were found to be similar with other populations investigated in this study. However, there is a significant frequency difference for IL-6 and IL-10 genotypes between populations. Conclusions The current population study provided more reference values for these polymorphisms and generated a control group to be used in further association studies especially for transplantation, GVHD, autoimmune and malign disease.