Dinucleotide repeat polymorphisms in the signal transducers and activators of transcription 6 (Stat6) gene in children with allergic diseases

Abstract

Background: Signal transducers and activators of transcription 6 (Stat6) is involved in the interleukin (IL)-4 and IL-13 signaling pathway. The aim of the present study was to evaluate whether polymorphisms in the 5′-flanking region of the Stat6 gene are associated with allergic diseases in Japanese children. Methods: The Stat6 gene polymorphisms were genotyped by polymerase chain reaction (PCR) fragment length polymorphism analysis and the IL-4 receptor Ile50Val polymorphism was examined using PCR methods. Results: Novel dinucleotide repeat polymorphisms were found in the 5′-flanking sequences, positioning at −865 (Pro A) and −690 (Pro B) of the Stat6 gene starting codon. The GT repeats in the 5′-flanking sequences were highly polymorphic (Pro A: 14–29 repeats; ProB: 14–20 repeats) with no significant differences in the frequency of allelic and genotypic distributions observed between allergic subjects and controls. In the GT repeat polymorphism of Stat6 exon 1, there was a significant difference in the frequency of genotypic distribution between the two groups (P = 0.003). The Stat6 exon 1 variant had significant linkage disequilibrium with Pro B variants, but not with Pro A. The GT repeat polymorphism was not associated with the IL-4 receptor Ile50Val polymorphism. Conclusions: Variants of the Stat6 gene may be useful markers for predicting allergic diseases in Japanese children.

Keywords

• atopy
• dinucleotide repeat polymorphism
• interleukin-13
• interleukin-4
• signal transducers and activators of transcription 6 (Stat6)