Polymorphism of the interferon-γ gene and risk of tuberculosis in a southeastern Chinese population

The aim of this study is to examine the influence of the +874 A/T and +875 CA microsatellite single nucleotide polymorphisms (SNPs) of the interferon-gamma gene (IFNG) on patients with tuberculosis (TB) in the southeastern Chinese population. Genomic DNA from patients with TB (n = 301) and ethnically matched controls (n = 310) was genotyped for the two SNPs by DNA sequencing and short tandem repeat-polymerase chain reaction (PCR) method. Our results demonstrated the AA genotype of +874 A/T IFNG was associated with TB (odds ratio, 1.98; 95% confidence interval = 1.08-3.63; p = 0.035). By grouping alleles into 12 and non-12 CA repeats at the +875 CA microsatellite, the homozygous non-12/non-12 CA repeats genotype yielded the same significant trend as that observed in the +874 AA genotype. The results indicate a positive association of IFNG polymorphism with TB. Data also provide genetic evidence supporting the multiple disease hypothesis, which emphasizes that many disease genes have been involved. (C) 2008 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.