Additionally, we conducted a meta-analysis with the rs7574865 SNP in STAT4 (1392 T1D patients and 1629 controls) and the rs1990760 SNP in IFIH1 (25092 T1D patients and 28544 controls) to examine their association with T1D.
Our meta-analysis revealed that the STAT4 rs7574865 polymorphism is associated with four autoimmune diseases with systemic pathology, including systemic lupus erythematosus (OR = 1.52; 95% CI = 1.48 - 1.56, P<1.0 × 10(-16)), rheumatoid arthritis (OR = 1.27; 95% CI = 1.21 - 1.33, P < 1.00 × 10(-16)), systemic sclerosis (OR = 1.38; 95% CI = 1.27 - 1.50, P < 1.44 × 10(-14)), and primary Sjogren's syndrome (OR = 1.32; 95% CI = 1.01 - 1.73, P = 4.40 × 10(-2)), while no association was found with type I diabetes, juvenile idiopathic arthritis, ulcerative colitis and Crohn's disease.
One of the two SNPs (rs7574865) was strongly associated with T1D in Northeastern Chinese population compared to healthy controls (P < 0.05), whereas the other tested SNP (rs3024866) demonstrated no significant relationship.
Our results indicate that whilst allele T of the STAT4 rs7574865 gene polymorphism is associated with susceptibility to T1D, it is not associated with increased risk for and T2D, and thus does not represent a common genetic factor for diabetes.
The association of STAT4 polymorphism rs7574865 with RA was validated in patients of Spanish origin (for T versus G, P = 1.2 x 10(-6), odds ratio [OR] 1.59, 95% confidence interval [95% CI] 1.31-1.92), and the association was described for the first time in both clinical forms of inflammatory bowel disease, Crohn's disease and ulcerative colitis (for T versus G, P = 0.006, OR 1.29, 95% CI 1.07-1.55), and in type 1 diabetes mellitus (for T versus G, P = 0.008, OR 1.36, 95% CI 1.07-1.71).
Here we demonstrate for the first time, in a genetically homogeneous population, the association of the STAT4 rs7574865 G/T polymorphism, which has been shown to be associated with these autoimmune diseases, with susceptibility to type 1 diabetes (T1D).
When we stratified T1D patients into early-onset and late-onset subgroups on the basis of fewer or more than 7.8 years of age at diagnosis, however, the minor alleles of three SNPs (rs7574865, rs8179673, and rs10181656) showed a significant association with susceptibility to T1D in the early-onset subgroup (i.e., rs7574865, OR = 1.44 [1.03-2.01], P < 0.05), but not in the late-onset subgroup, suggesting that STAT4 is related to earlier development of T1D.
We conducted a case-control study, enrolling 173 T1D patients and 191 healthy controls from northeastern Brazil, to assess the distribution of the rs7574865 and rs3024839 SNPs in STAT4 and the rs3747517 and rs1990760 SNPs in IFIH1 in T1D and APSIII patients.
One of the two SNPs (rs7574865) was strongly associated with T1D in Northeastern Chinese population compared to healthy controls (P < 0.05), whereas the other tested SNP (rs3024866) demonstrated no significant relationship.