Genetic association of Fc receptor-like glycoprotein with susceptibility to Graves' disease in a Chinese Han population.

BACKGROUND: Graves' disease (GD) is recognized as a most frequent form of autoimmune thyroid disease, but the etiology underlying GD still remains unclear. Among the thyroid-specific and immune-modulating genes involved in susceptibility to GD, FCRL3 polymorphisms have been demonstrated to be associated with GD in independent studies. However, considering the limited sample size and statistical power of previous studies, there is no study analyzing this relationship systematically. Therefore, this investigation was aimed to perform a case-control study in a Chinese population and a meta-analysis including relevant studies was carried out to confirm a potential correlation between SNPs investigated and risk of GD.

METHODS AND MATERIALS: Seven single nucleotide polymorphisms (SNPs) were selected in this case-control study involved with 671 GD patients and 706 controls. Later, a meta-analysis including seven case-control studies related to GD susceptibility and FCRL3 polymorphisms was carried out. T-test and chi-square test were utilized to find if difference in clinical variables existed between case and control subjects. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the association between GD susceptibility and FCRL3 polymorphisms.

RESULTS: Three polymorphisms, namely, FCRL3_3C, FCRL3_5C and FCRL3_6A, were significantly associated with increased risk of GD in terms of a Chinese Han population in both dominant model [OR=1.33 (95% CI: 1.04-1.69), OR=1.34 (95% CI: 1.05-1.70) and OR=1.36 (95% CI: 1.07-1.75), respectively] and allelic model [OR=1.27 (95% CI: 1.10-1.48), OR=1.28 (95% CI: 1.11-1.49) and OR=1.23 (95% CI: 1.06-1.43), respectively]. Further meta-analyses indicated that the effects of FCRL3_3C, FCRL3_5C and FCRL3_6A on susceptibility to GD varied between Asians and Caucasians.

CONCLUSIONS: This case-control analysis demonstrated that FCRL3_3, FCRL3_5 and FCRL3_6 polymorphisms were associated with significantly elevated risk of GD in a Chinese population. Furthermore, the following meta-analysis confirmed that FCRL3_3, FCRL3_5 and FCRL3_6 polymorphisms could increase susceptibility to GD only in Asians, rather than in Caucasians.