Association of the miR-146a, miR-149, miR-196a2 and miR-499 polymorphisms with susceptibility to pulmonary tuberculosis in the Chinese Uygur, Kazak and Southern Han populations

Background: Single nucleotide polymorphisms (SNPs) within precursor microRNAs (miRNAs) can affect miRNAs expression, and may be involved in the pathogenesis of pulmonary tuberculosis (TB). This study aimed to investigate potential associations between the four precursor miRNA SNPs (miR-146a C > G, miR-149 T > C, miR-196a2 T > C, and miR-499 T > C) and susceptibility to pulmonary TB in the Chinese Uygur, Kazak, and Southern Han populations. Methods: A case-control study was performed on Chinese Uygur (n= 662), Kazak (n= 612), and Southern Han (n= 654) populations using the PCR-PFLR method. The allele and genotype frequencies for all populations were analyzed. Linkage disequilibrium was performed, and different models of inheritance were tested. Results: The allele and genotype frequencies of the miR-499 SNP were significantly different between the TB patients group and the healthy control group in the Uygur population, and were found to be codominant, dominant, recessive and additive models in association with pulmonary TB. The haplotype CTCC showed significant correlation with pulmonary TB. The allele and genotype frequencies of miR-146a and miR-196a2 SNPs were significantly different between the two groups in the Kazak population. The miR-146a SNP was found to be codominant, recessive and additive models, whereas, the miR-196a2 SNP was found to be codominant, dominant, and additive models in association with pulmonary TB. The haplotypes TCCC and CCCT showed significant correlation with pulmonary TB. Conclusions: The results suggested that susceptibility to pulmonary TB may be closely related to individual differences caused by genetic factors among different ethnic groups in China.