title: Association of single nucleotide polymorphisms in interleukin 12 (IL-12A and -B) with asthma in a Chinese population.
abstract: Increasing evidence has indicated that genetic variants may contribute to immune dysregulation and susceptibility to noninfectious inflammatory diseases. Cytokines, including interleukin 12 (IL-12), play a key role in the regulation of the immune system. The aim of this study was to investigate whether single nucleotide polymorphisms (SNP) in IL-12A and IL-12B were associated with asthma in a Chinese population. Genotype characteristics were determined in 197 asthma patients and 369 controls by the polymerase chain reaction-restriction fragment length polymorphism method and DNA sequencing assay. The genotype and allele frequencies of IL-12A rs568408 demonstrated significant differences between cases and controls (p < 0.001). The AC genotype of rs3212227 was associated with a significantly decreased risk of asthma compared with the AA genotype (p = 0.036). The subjects carrying combined genotypes (rs568408 AG and rs3212227 AC/CC) at both loci had a 2.05-fold increased asthma risk compared with those carrying all other genotypes (p = 0.001). In contrast, individuals carrying combined genotypes of rs568408 GG and rs3212227 AC/CC were associated with a significantly decreased risk of asthma compared with those carrying the combined genotypes of rs568408GG and rs3212227AA (p = 0.009). No significant difference was reported for rs2243115 between cases and controls. These results suggest that the SNPs in IL-12A rs568404 and IL-12B rs3212227 may individually and jointly contribute to the risk of asthma in a Chinese population.
authors.affiliation: Department of Forensic Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, China.
authors.forename: Tianyi
authors.initials: T
authors.lastname: Chen
authors.forename: Weibo
authors.initials: W
authors.lastname: Liang
authors.forename: Linbo
authors.initials: L
authors.lastname: Gao
authors.forename: Yanyun
authors.initials: Y
authors.lastname: Wang
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.forename: Lushun
authors.initials: L
authors.lastname: Zhang
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000483:Alleles; D044466:Asian People / Q000235:genetics*; D001249:Asthma / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D053765:Interleukin-12 Subunit p35 / Q000235:genetics*; D053762:Interleukin-12 Subunit p40 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D055815:Young Adult
chemical_list: D053765:Interleukin-12 Subunit p35; D053762:Interleukin-12 Subunit p40