SMAD3 rs36221701 T>C polymorphism impacts COPD susceptibility in the Kashi population.

Small mother against decapentaplegic (SMAD) family member 3 (SMAD3) is well correlated with the inflammatory response of chronic obstructive pulmonary disease (COPD). A previous study indicated that the single nucleotide polymorphism (SNP) rs36221701 of SMAD3 was related to the risk of inflammatory disease. Hence, given the pathogenesis of COPD is intently associated with smoking and gene polymorphism, this study aims to analyze the relationship between SMAD3 rs36221701 and COPD susceptibility, and to explore whether the interaction is related to smoking status. We studied the association between the rs36221701 and rs34307601 of SMAD3 and COPD susceptibility, a total of 541 COPD patients and 534 controls of the Uyghur population were recruited at the First People's Hospital and the village of Kashi. The interrelation of the two SNPs with the risk of COPD was determined by calculating odds ratio (OR) and 95% confidence interval (95% CI). We found a significant association between the rs36221701 and COPD risk in the non-smoking population. TC genotype showed a significant decreased association with COPD risk (OR = 0.59, 95% CI = 0.41-0.83, P < 0.05), but CC genotype can increased the COPD risk (OR > 1, P < 0.05). In addition, COPD susceptibility was not related to the genetic variations in the rs34307601 (P > 0.05). In conclusion, we confirmed that the SMAD3 rs36221701 may be associated with COPD susceptibility in the Chinese Uyghur population, especially among non-smokers. Our data provide new light for the relationship between SMAD3 gene polymorphisms and COPD susceptibility in the Chinese Uyghur population.