Implication of VDR Rs7975232 and FCGR2A Rs1801274 Gene Polymorphisms in the Risk and the Prognosis of autoimmune Thyroid Diseases in the Tunisian Population.

Hashimoto's thyroiditis (HT) and Graves' disease (GD) are autoimmune thyroid diseases (AITD) that cause hypothyroidism and hyperthyroidism, respectively. The vitamin D receptor (VDR) and the Fey receptor IIA (FcγRIIA), are implicated in the etiology of AITD. This study was conducted to examine the implication of VDR rs7975232 and FCGR2A rs 1801274 variations in the susceptibility and the prognosis of AITD in the Tunisian population. The rs7975232 and rs1801274 (R131H) polymorphisms were analyzed in 162 controls and 162 AITD patients (106 HT and 56 GD) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and amplification of refractory mutation system-PCR (ARMS-PCR), respectively. No significant difference was demonstrated for the rs7975232 between patients and controls. However, a significant association was shown between the rs1801274 polymorphism and AITD or HT in the dominant (p = 0.03 or p = 0.01), codominant (p = 0.019 or p = 0.026) and allelic (p = 0.011 or p = 0.012) models. The rs7975232 was associated with the absence or the presence of anti-thyroglobulin antibody, with the age of AITD and GD patients during the first diagnosis (p = 0.01 and p = 0.009, respectively) and with a high T4 level at the beginning of HT disease. However, the FCGR2A gene polymorphism was associated with a low T4 level at the beginning of GD disease. In conclusion, this study indicates that only the FCGR2A variation could be related to AITD and HT susceptibility and that VDR and FCGR2A gene variations constitute factors to prognosticate the severity of AITD, HT and GD.

Polymorphisms in TSHR gene and the risk and prognosis of autoimmune thyroid disease in Tunisian population.

BACKGROUND: Autoimmune thyroid diseases (AITD) including Graves' disease (GD) and Hashimoto's thyroiditis (HT) are complex genetic diseases. TSHR is considered as candidate gene in GD. This finding prompted us to investigate the association of TSHR gene polymorphism with the risk and the prognosis of AITD in Tunisia. METHODS: A total of 84 healthy controls and 91 patients with AITD (69HT and 22 GD) were genotyped for TSHR rs74067403A>G polymorphism and 134 healthy controls and 149 patients with AITD (98 HT and 51 GD) were genotyped for TSHR rs1054708 T>C polymorphism. RESULTS: For rs1054708, we found an association between HT, AITD and the heterozygous genotype TC, the mutated genotype CC and the genotypes presented the mutated allele C (TC+CC) and with mutated allele C. The heterozygous genotype TC and the genotypes that presented the mutated allele C of rs1054708 are associated with male patients with AITD evenly the heterozygous genotype TC is associated with age of onset of disease. CONCLUSIONS: These preliminary results suggest that TSHR rs1054708 polymorphism may be a protective factor against HT and AITD. This polymorphism can affect the etiology of AITD between men and women and also by age.