Several interleukin-4 and interleukin-13 gene single nucleotide polymorphisms among Chinese asthmatic patients

Asthma is a common respiratory disease associated with airway hyperactivity and high total serum immunoglobulin E (IgE) levels. The asthmatic phenotypes are widely considered to be caused by environmental effects on genetically predisposed individuals. Interleukin (IL)-4 and IL-13 act on B cells and regulate the IgE production, and the single nucleotide polymorphisms (SNPs) in the IL-4 and IL-13 genes are implicated in the pathogenesis of asthma. To study the association of IL-4 and IL-13 gene polymorphisms with asthma, we sequenced the promoter regions and exons of IL-4 and IL-13 genes in two groups: one (spouses group) consisted of 13 pairs of asthmatic patients (cases) and their unaffected spouses (controls); the other (parents group) consisted of 11 pairs of asthmatic children (cases) and their unaffected father/mother (controls). In total, seven polymorphisms were identified, one novel and six previously reported. However, according to the results of the statistical analysis we performed, no statistically significant association of these SNPs and asthma was observed (p > 0.05). Asthma is largely determined by the accumulation of several certain genetic variations other than one or two SNPs. Future function studies may be able to help us reveal the significance of genetic variants we identified in this study.