A Smad3 Gene Polymorphism In Chronic Obstructive Pulmonary Disease In Han Population Of Southwest China

Aim To determine the frequencies of one polymorphism in the intron 5 ofSmad 3 gene in Southwest Chinese Han population and to investigate thesusceptibility of this population to chronic obstructive pulmonary disease(COPD).Methods To examine the interaction between a Smad 3 gene polymorphismand COPD, we carried out a case-control study.259 patients with COPD wererecruited from respiration unit in West China Hospital of Sichuan University.245 unrelated, age-matched subjects who had no known chronic respiratorydiseases or family disorders and were taking no medications acted as controlsubjects. The polymorphism of rs2278546 in intron 5 of Smad 3 gene wasdetermined by the TaqMan polymerase chain reaction(PCR) method.Results No deviation from Hardy-Weinberg equilibrium were noted in bothCOPD and control groups.The frequencies of polymorphic genotypes inrs2278546 of Smad 3 in COPD group were A/A, 37.4％; A/G, 48.3％and G/G,14.3％. The frequencies of polymorphic genotypes in control group were A/A,34.3％; A/G, 43.3％; and G/G, 22.4％. The allele frequencies of COPD group were A,61.6％;G,38.4％.The allele frequencies of control group were A,55.9％;G;44.1％.The X~2 of COPD and control groups were 5.634,3.336respectively. There were no marked differences between two groups ingenotype frequencies and allele frequencies (p＞0.05). A simple classificationof disease severity into four stages of COPD was recommended by GlobalInitiative for Chronic Obstructive Lung Disease.The X~2 of polymorphicgenotypes in control group and stageⅠof COPD, stageⅠand stageⅡofCOPD, stageⅡand stageⅢof COPD, stageⅢand stageⅣof COPD were3.026 (p＞0.05), 3.476 (p＞0.05), 10.085 (p＜0.05), 0.683 (p＞0.05). Using logisticregression analysis stratified with confounding factors, the results betweenCOPD and control group were (1)A/A: p=0.055 OR=1.684 (2)A/G: p=0.044OR=1.685 (3)G/G: p=0.055 OR=0.594.Conclusions The A/G genotype of rs2278546 in the Smad 3 gene may beassociated with COPD in Southwest Chinese Han population.And thefrequencies of genotype of the stageⅡof COPD were different from those ofstageⅢ. Objective To determine the frequencies of polymorphism in variablenumber of tandem repeat in intron2 (vntr2) of IL-4 in Han and Weipopulations of West China and to investigate the susceptibility of the twopopulations to chronic obstructive pulmonary disease (COPD).Methods Vntr2 region of the IL-4 gene were amplified from 259 ChineseHan patients with COPD and 245 age- and gender-matched Han controlswithout chronic respiratory diseases, and 22 Wei COPD patients and 45 Weicontrols without chronic respiratory diseases by PCR technique respect-tively. Association between IL-4 polymorphism and the two populationswere analyzed by SPSS 13.0.Results No deviation from Hardy-Weinberg equilibrium was noted in bothCOPD and control groups of Han and Wei populations. 1.The genotypefrequencies of IL-4 gene in COPD and control groups of Han populationwere 1/1,52.1％;1/2,42.5％;2/2,5.4％and 1/1,46.5％;1/2,45.7％;2/2,7.8％res-pectively. The allele frequencies of COPD and control groups were1,73.4％;2,26.6％and 1,69.4％;2,30.6％.The X~2 of genotype and allele fre-quencies of Han population were 2.159 and 1.946 respectively. There was nodifference between COPD patients and controls in genotype and allele frequencies in Han population(p＞0.05). A simple classification of diseaseseverity into four stages of COPD was recommended by Global Initiative forChronic Obstructive Lung Disease.The X~2 of polymorphic genotypes in control group and stageⅠof COPD, stageⅠand stageⅡof COPD,stageⅡandstageⅢof COPD, stageⅢand stageⅣof COPD were 5.036(p＞0.05), 7.740(p＜0.05), 2.26(p＞0.05) and 1.526 (p＞0.05). Using logistic regression analysisstratified with confounding factors,the results between COPD and controlgroups were (1)1/1: p=0.531 OR=1.127 (2)1/2:p=0.531 OR=0.887 (3)2/2:p=0.423 OR=0.734.2. The frequencies of genotypes in COPD and control groups of Wei popu-lation were 1/1,22.7％,53.3％; 1/2,59.1％,44.4％; and 2/2,18.2％,2.2％respect-ively. The allele frequencies of the two groups were 1,52.3％,75.6％; 2, 47.7％,24.4％. The X~2 of genotype and allele frequencies were 8.885 and 7.351. The pvalues were 0.012 and 0.007 respectively (both＜0.05). Significant differencewas observed between COPD patients and controls in Wei population.The X~2of genotypes in stageⅡand stageⅢof COPD was 4.581(p＞0.05). Usinglogistic regression analysis stratified with confounding factors, the resultsbetween COPD and control groups were (1)1/1:/)=0.013 OR=0.161 (2)1/2:p=0.013 OR=6.203 (3)2/2:p=0.019 OR=19.322.Conclusions There may be no association between the vntr2 of IL-4 geneand COPD in Han population of West China. The genotype frequencies of thestageⅠof COPD was different from those of stageⅡ. But the polymorphismsof the vntr2 of IL-4 gene might be associated with COPD in Wei populationof West China.