Associations of GWAS-Supported Non-MHC Genes with Autoimmune Thyroiditis in Patients with Type 1 Diabetes.

Purpose A genome-wide association study (GWAS) in Caucasian population identified five non-MHC genes (PHTF1, PTPN22, MAGI3, BCL2L15, and QRFPR) associated with risk of the co-occurrence of autoimmune thyroid diseases (AITD) and type 1 diabetes (T1D). The aim of this study is to replicate these associations with AITD in patients with T1D in Chinese Han population. Patients and methods A case-control study was designed. Five single-nucleotide polymorphisms (SNPs) PHTF1 rs1111695, PTPN22 rs1217407, MAGI3 rs2153977, BCL2L15 rs2358994, and QRFPR rs7679475 were genotyped in 489 patients with T1D. Associations between genotypes and AITD risk were analyzed with logistic regression model. Results AITD occurred in 159 (32.5%) patients. When adjusting multiple factors by logistic regression, QRFPR rs7679475 was significantly associated with an increased risk of AITD in T1D patients in codominant model (G/G vs A/A, OR 2.93; 95% CI 1.44-5.96; P = 0.003), dominant model (G/A-G/G vs A/A, OR 1.81; 95% CI 1.17-2.79; P = 0.007) and recessive model (G/G vs A/A-G/A, OR 2.28; 95% CI 1.17-4.43; P = 0.015). Furthermore, we found a significant interaction between rs7679475 and female (P interaction = 0.005). In silico analysis indicated that rs7679475 is located in histone modification marked region and can change the binding of regulatory motifs. Conclusion Our results suggested that QRFPR rs7679475 may influence the risk of AITD in patients with T1D in Chinese Han population, and this effect may be modulated by sex.