Interferon-gamma gene and interferon-gamma receptor-1 gene polymorphisms in children with tuberculosis from Turkey.
Macrophage activation by interferon-gamma (IFN-gamma) is important in host resistance to tuberculosis (TB). In this study, the relationships of the +874 T/A polymorphism in the first intron of the IFN-gamma gene and intronic (CA)n polymorphic microsatellite marker of the interferon-gamma receptor 1 (IFN-gammaR1) gene to TB susceptibility were investigated in children. Forty children with TB and 67 age-matched controls were included. There were no significant differences between the allele frequencies and genotype frequencies of patient and control groups for the polymorphism +874 T/A in the IFN-gamma gene. Differences that were not statistically significant were found between the group of children with TB and the control group for the allelic markers (170 and 180) in the IFN-gammaR1 gene. The incidence of the allele 170 was higher in patients (30.9%) than in controls (17.4%), whereas the allele 180 was found to be more common in controls (9% vs 1.2%). In conclusion, no significant association was observed between the +874 T/A polymorphism found in the first exon of the IFN-gamma gene and TB susceptibility in Turkish children.