IFN-γ T/A +874 Gene Polymorphism in Type 1 Diabetes Mellitus of Iraqi Children

Abstract

This study included 50 blood samples collected from children with mean age 8-12 years. Thirty five blood samples were collected from children with Type 1 Diabetes Mellitus (T1D) with mean age 9.4±0.34 years, and 15 blood samples collected from healthy children as a control sample with mean age 10.9±0.38 years. Immunogenetic study was done on collected blood samples. Concentrations of IFN-γ were estimated from T1D patient and control samples by using Elisa instrument. The concentration of this interferon was 1.575 pg/ml in T1D patient sample in comparison with 0.921 pg/ml in control sample. Significant differences of this interferon concentration were found between T1D patient and control samples when Mann-Whitney U test was used. Gene polymorphism of IFN-γ T/A +874 gene was studied by using Amplification refractory mutation system (ARMS-PCR) technique. The results of gel electrophoresis for IFN-γ T/A +874 gene revealed the presence of two alleles, A and T and three genotypes TT, TA and AA. The percentage frequency of T allele was higher from the A allele in T1D patient sample, whereas the percentage frequency of T allele was higher from A allele in control sample. The frequencies of A allele in T1D patient sample was significantly different with the same allele in control sample when Fisher’s test was used. The odds ratio (OR) and confidence Intervals (CI) values showed that the A allele was etiological faction (EF) and correlated with the disease, whereas the T allele was significantly different in control sample in comparison with T1D patient sample when Fisher’s test was used and become as preventive faction (PF). The results of ARMS-PCR technique for the IFN-γ T/A +874 gene were analyzed by using Hardy-Weinberg equilibrium. The TT genotype percentage in control sample was higher in comparison with the T1D patient sample and significant difference was found by using Fisher’s test. The TT genotype revealed as preventive faction from the disease, whereas the TA genotype percentage was significantly different in T1D patient sample in comparison with control sample. The TA genotype also revealed as etiological faction and correlated with the disease. The percentage of AA genotype in T1D patient sample was higher in comparison with control sample with no significant differences and this genotype revealed as etiological faction and correlated with the disease.