Associations of genetic variants within TYK2 with pulmonary tuberculosis among Chinese population

Abstract

Background: Pulmonary tuberculosis (PTB) is a common infectious disease caused by mycobacterium tuberculosis (MTB) and the present study aims to explore the associations of genetic variants within tyrosine kinases 2 (TYK2) with PTB incidence.

Methods: A population-based case control study including 168 smear-positive PTB cases and 251 controls was conducted. Five single nucleotide polymorphisms (SNPs) including rs280520, rs91755, rs2304256, rs12720270, rs280519 located within TYK2 gene were selected and MassARRAY® MALDI-TOF system was employed for genotyping. SPSS 19.0 was adopted for statistical analysis, non-conditional logistic regression was conducted. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed to estimate their contributions to PTB incidence.

Results: In the overall study population, rs91755 TT and rs280519 AA genotypes were found to be associated with reduced PTB risk (OR = 0.34, 95% CI: 0.16-0.72; OR = 0.38, 95% CI: 0.18-0.79, respectively). After stratification for sex, we found that among the male population, rs91755TG/TT, rs12720270AG/GG and rs280519AG/AA genotypes were associated with reduced PTB risk (OR = 0.41, 95% CI: 0.21-0.80; OR = 0.44, 95% CI: 0.21-0.94; OR = 0.42, 95% CI: 0.21-0.82, respectively). After stratification for age, we found that among those aged <60 years, rs91755TT and rs280519AA genotype were associated with reduced PTB risk (OR = 0.29, 95% CI: 0.09-0.90; OR = 0.34, 95% CI: 0.11-1.08, respectively); while rs2304256AC/AA genotype was associated with increased PTB risk (OR = 2.68, 95% CI: 1.05-6.85). Haplotype analysis revealed that AGAAG and ATCGA (Combined with rs280520, rs91755, rs2304256, rs12720270 and rs280519) were associated with increased (OR = 1.54, 95% CI: 1.01-2.37) and decreased PTB risk (OR = 0.70, 95% CI: 0.52-0.94), respectively.

Conclusions: The genetic variants located within TYK2 including rs91755, rs12720270 and rs280519 were found to be associated with modified PTB risk and the SNPs had potential to be the biomarkers to predict PTB incidence risk.

Keywords: MTB; PTB; SNPs; TYK2.