β2-adrenergic receptor polymorphisms and asthma in the North Indian population

Abstract

Introduction: The β2-adrenergic receptor (ADRB2) polymorphisms are known to be functionally relevant and disease modifying in subjects with asthma. However, the association of these polymorphisms with asthma remains to be established. Our objective is to investigate the association of the ADRB2 polymorphisms and haplotypes with asthma in North Indian subjects. Methods: A subset of 101 unrelated cases and 55 unrelated unaffected individuals were used for a case–control disease-association test. Results: Ten variable single nucleotide polymorphism (SNP) sites within a span of 2.193 kb were identified in the ADRB2 gene by the sequencing and genotyping of 351 bronchial asthma patients and healthy individuals. The distributions of genotype and allele frequencies for individual SNPs in the ADRB2 gene and ADRB2 haplotype frequencies were estimated in unrelated asthmatics and healthy individuals. No significant association was observed between ADRB2 genotypes and alleles with disease status after Bonferroni correction for multiple testing (reference p value = 0.0083). However, haplotype GGCTTTGCAA was found to be significantly associated with asthma (p = 0.021) in the studied population. Conclusion: Our results suggest that there is likely to be a functional significance of the ADRB2 gene with asthma.