S2 and T2 ADAM33 polymorphisms and haplotype associated with asthma in the Zhuang population in Guangxi, China

Objective: Discovered through positional cloning, a disintegrin and metalloproteinase domain-containing protein 33 (ADAM33) represents a novel gene that may increase asthma risk in different ethnic groups. This study was conducted to determine whether the single nucleotide polymorphisms (SNPs) in ADAM33 are associated with asthma risk in the large population of ethnic minorities in Guangxi Zhuang, China. Methods: A total of 226 subjects were involved in the study, including 119 normal controls and 107 asthmatic patients. Polymerase chain reactionrestriction fragment length polymorphism was used to genotype ADAM33 polymorphisms S2 and T2. Chi-square test and logistic regression model were used to analyze the data using SPSS version 16.0 and SHEsis. Results: The allele and genotype frequencies of S2 SNP statistically varied between the asthmatic cases and controls. S2 SNP was determined to be statistically associated with asthma in allele comparison (OR: 0.423, 95% CI: 0.273-0.654, P<0.001), heterozygote genotype comparison (OR: 0.527, 95% CI: 0.302-0.920, P=0.024), and dominant model comparison (OR: 0.421, 95% CI: 0.244-0.724, P=0.002). The CA and GG haplotypes of S2 and T2 in the control groups were higher than those in the asthmatic cases with statistical significance, whereas the haplotype CG was significantly higher in the latter group. Conclusion: S2 (C>G) polymorphisms may reduce the risks of asthma among the large population of Guangxi Zhuang.