Signal transducers and activators of transcription 6 (Stat6) variants in childhood and adult asthma

Background: Signal transducers and activators of transcription 6 (Stat6) is a key transcription factor involved in interleukin (IL)-4 and IL-1 3-mediated biological responses. Recently, we reported the association between the dinucleotide (GT) repeat polymorphism in the first exon of Stat6 and allergic subjects in a Japanese population. The aim of the present study was to evaluate whether this GT repeat polymorphism is associated with bronchial asthma, including childhood asthma and atopic and non-atopic adult asthma. Methods: Stat6 gene polymorphisms were genotyped by polymerase chain reaction (PCR) fragment length polymorphism analysis. Results: In the first exon of Stat6, polymorphic PCR products were classified into six alleles (12–17 GT repeats). A significant difference was found in the genotypic frequency of the GT repeat polymorphism between controls and child asthmatics (P = 0.015), but not atopic or non-atopic adult asthma. The frequency of the 15 repeat allele (wild type) was lower in child asthmatics than in controls (P = 0.0047; odds ratio (OR) 1.6, 95% confidence interval (CI) 1.16-2.23), whereas shorter repeat alleles (12, 13 and 14 GT repeat) were higher in child asthmatics than in controls (P = 0.0064; OR (95%CI) 1.66 (1.15-2.39)). Conclusion: Genetic variations in the Stat6 gene may be associated with a predisposition for childhood asthma.