Abstract:
Objective To investigate the association between Lys469Glu and Arg241Gly of intercellular adhesion molecule 1(ICAM-1) gene polymorphisms and genetic susceptibility on childhood asthma.
Methods Twenty-five primary schools were selected from 40 schools located in a suburban district of Beijing. The parents of the students of 1st~5th grades were asked to complete a questionnaire, then 293 cases and 668 controls were obtained from this study population. The influence factors on asthma were acquired by another questionnaire. DNA samples were extracted from buccal cells. Two single nucleotide polymorphisms(SNPs) in ICAM-1 gene, including Lys469Glu and Arg241Gly were detected by polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP). The association between genotypes and childhood asthma were analyzed by Logistic regression.
Results The genotypes AG or GG and AG of ICAM-1 Lys469Glu decreased the risk of asthma(P < 0.05), the odds ratios (OR) were both 0.73. The frequency of G allele in cases was 28.5%, and that in controls was 33.0%. The former was lower than the latter, which was marginally significant, P=0.058. When there was passive smoking, the children with genotype AG or GG had lower risk of asthma compared with those with genotype AA, OR=0.73 (P=0.066). The decreased risks were also found for those with genotype AG or GG in the subgroup using coal for cooking (OR=0.57, 95%CI 0.33-0.97)and the subgroup having many rats indoors (OR=0.65, 95%CI 0.46-0.93)compared with those with genotype AA. No association was found between Arg241Gly polymorphism and childhood asthma.
Conclusion The variation of ICAM-1 Lys469Glu is significantly related to genetic susceptibility on childhood asthma, possibly decreasing the risk of asthma.