ASAP1 gene polymorphisms are associated with susceptibility to tuberculosis in a Chinese Xinjiang Muslim population

Seven single-nucleotide polymorphism (SNP) sites located in ASAP1 gene have been found associated with tuberculosis (TB) susceptibility by genome-wide association studies in Russia. The case-control study was carried out to test whether these seven SNPs were associated with susceptibility to TB in a Chinese Xinjiang Muslim population. The seven SNPs were genotyped in a case-control design that included 780 Xinjiang Muslim subjects (400 TB patients and 380 controls). Multiplex PCR and direct sequencing were used to detect ASAP1 gene polymorphisms. Hardy-Weinberg equilibrium test was performed to test whether the sample was from genetic equilibrium population. The associations of SNPs with TB risk were determined by the distributions of allelic frequencies and different genetic models. Significant differences of the allelic distribution of rs4733781 and rs1017281 in ASAP1 gene were observed between control group and TB group. A allele of rs4733781 was associated with TB risk (TB vs. control, OR=1.242; 95% CI: 1.004-1.537, P=0.046); While in rs1017281 site, G allele was associated with increased risk for TB (TB vs. control, OR: 0.792, 95% CI: 0.643-0.976, P=0.028). The recessive model of rs4733781 (CC vs. AC+AA) in Xinjiang Muslim populations was associated with a lower TB risk [P=0.003, OR=0.51 (0.324-0.802)], while the recessive model of rs1017281 (GG vs. AG+AA) was associated with a higher TB risk [P=0.011, OR=1.792 (1.135-2.828)]. Using case-control analysis, we identified that two genetic polymorphism sites in the ASAP1 relate to host susceptibility of TB in a Chinese Xinjiang Muslim population.