Genetic Polymorphisms of miR-149 Associated with Susceptibility to Both Pulmonary and Extrapulmonary Tuberculosis.

Background: Single nucleotide polymorphisms (SNPs) within precursor microRNAs (miRNAs) can affect the expression of the miRNAs and may be involved in the pathogenesis of pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) patients. Aims: We investigated the potential associations among four precursor miRNA SNPs (miR-149 A>G, C>T; miR-196a2 C>T; miR-499 C>T) and their susceptibility to both PTB and EPTB. Methods: The study included 380 PTB patients, 242 EPTB patients, and 606 healthy control (HC) subjects from a Chinese Han population. We determined the miRNA relative expression levels from 10 HCs and 10 tuberculosis (TB) patients by quantitative PCR. Results: We found that the PTB group had a significantly lower miR-149 level (p < 0.05) versus the HCs. The allele and genotype frequencies of the miR-149 SNPs were significantly different between the TB patients and the HC group. The C allele at the rs2292832 and the A allele at the rs71428439 locus were associated with susceptibility to EPTB. The C allele of rs2292832 was associated with an increased risk of EPTB compared with that of HCs (p < 0.01), and the A allele of rs71428439 was protective against EPTB (p < 0.01) and PTB (p < 0.01). Conclusions: We identified that genetic polymorphisms in miR-149 may be associated with susceptibility to both PTB and EPTB within a Chinese population.