The Protein Tyrosine Phosphatase Non-Receptor Type 22 C1858T Polymorphism Is a Joint Susceptibility Locus for Immunthyroiditis and Autoimmune Diabetes

Background: The lymphoid tyrosine phosphatase (LYP) encoded by the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene is a strong inhibitor of T cells. The single nucleotide polymorphism (SNP) C1858T within the PTPN22 gene was recently associated with autoimmune thyroid disease (AITD) and type I diabetes (T1D). The purpose of this study was to examine the joint association of this polymorphism with the co-occurrence of AITD and T1D....