Associations of STAT4 rs7574865 G/T and PTPN22 (rs2488457 G/C and rs2476601 C/T) polymorphisms with JIA have repeatedly been replicated in several Caucasian populations.
A single nucleotide polymorphism of PTPN22, 1858C>T (rs2476601), disrupts an interaction motif in the protein, and is the most important non-HLA genetic risk factor for rheumatoid arthritis and the second most important for juvenile idiopathic arthritis.
This meta-analysis confirms that the PTPN22 1858 C/T polymorphism is associated with JIA susceptibility in Europeans and shows that the MIF -173 C/G polymorphism may be associated with susceptibility to JIA.
This meta-analysis showed the association between the T-allele and the T/T genotype and JIA (OR = 1.34, P = 0.03; OR = 1.97, P = 0.02) but did not reveal the association between the PTPN22 C1858T polymorphism and IBD, psoriasis, multiple sclerosis, Addison's disease and Celiac disease.
Its +1858C>T (R620W) polymorphism has been shown to associate with a risk for multiple autoimmune diseases, including type 1 diabetes (T1D) and juvenile idiopathic arthritis (JIA).
The minor allele of the R620W missense single-nucleotide polymorphism (SNP; rs2476601) in the PTPN22 (protein tyrosine phosphatase non-receptor 22) gene has been reported to be associated with multiple autoimmune diseases, including type 1 diabetes, systemic lupus erythematosus, rheumatoid arthritis, juvenile idiopathic arthritis, autoimmune thyroiditis and vitiligo.