RESUMO
BACKGROUND: The ubiquitin conjugating enzyme E2L3 (UBE2L3) gene is associated with susceptibility to many autoimmune diseases. The aim of this study was to investigate the association between UBE2L3 gene and autoimmune thyroid diseases (AITDs) and their clinical phenotypes. METHODS: We genotyped five single-nucleotide polymorphisms (SNPs) rs131654, rs5754217, rs2298428, rs140489 and rs5998672 of UBE2L3 gene in case groups including 1028 patients with AITDs [676 cases of Graves' disease (GD) and 352 cases of Hashimoto's thyroiditis (HT)] and control group including 897 healthy individuals. The genotyping was performed with the method of polymerase chain reaction-ligase detection reaction (PCR-LDR). RESULTS: The frequencies of allele and genotype of five SNPs in gene UBE2L3 showed no statistically significant difference between case groups and control group, respectively. Moreover, no significant differences in frequencies of allele and genotype of five SNPs of the gene were found between clinical subphenotypes of AITDs and control group. Such subphenotypes included GD, HT, and thyroid associated ophthalmopathy (TAO). The negative results were also found in the frequency of other haplotypes of the gene except the haplotype of TCGGC, which was significantly higher in HT group than in control group (P = 0.031, OR = 1.441). CONCLUSIONS: The present findings indicate that TCGGC haplotype is associated with an increased risk of HT and UBE2L3 gene is likely to be a susceptibility factor to HT in a Chinese Han population.