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

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. 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. 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. Variants of the Stat6 gene may be useful markers for predicting allergic diseases in Japanese children. [ABSTRACT FROM AUTHOR]