C1858T functional variant of PTPN22 gene is not associated with celiac disease genetic predisposition.

Recent findings have demonstrated that the single nucleotide polymorphism 1858C-->T located at the P1 motif of the PTPN22 (protein tyrosine phosphatase nonreceptor 22) gene has functional relevance and is associated with a variety of autoimmune diseases. The aim of this study was to assess the role of the PTPN22 1858C-->T polymorphism in the genetic predisposition to celiac disease (CD). We analyzed a case-control cohort composed by 534 patients with CD and 653 healthy controls and additionally a panel of 271 celiac families. The PTPN22 1858C-->T genotyping was performed by TaqMan 5' allelic discrimination assay. We did not observed any statistically significant deviation after comparing allele and genotypic frequencies of PTPN22 1858C-->T between patients with CD and controls. Accordingly, the familial analysis did not reach statistically significant deviation in the transmission of PTPN22 1858C-->T alleles to the affected offspring. Therefore, our data suggest that the PTPN22 1858 single nucleotide polymorphism has no, or only a negligible, effect on CD susceptibility in this Spanish population.