In this article are presents the results of studying the characteristic features of the FCGRIIC gene in Hashimoto’s disease and the phenotypic role of the character of its mutations and polymorphisms in the development of this autoimmune pathology. The purpose of the study: to assess the role of polymorphism or mutation FCGR2C gene in autoimmune reaction in Hashimoto’s disease. Methods. 48 patients brought to the study with clinical signs of Hoshimoto’s disease were admitted to the departments of endocrinology and internal medicine of the Medical Faculty of the University of Ege. For the purpose of conducting a comparative analysis, 25 practically healthy individuals of the same age and sex without a diagnosis of Hashimoto’s thyroiditis and without a family history or genetic predisposition of the studied pathology were included in this study. Results. Based on the results of the clinical and laboratory studies, after the analysis of the whole coding region of the FCGRIIC gene, 12 new mutations were found and 7 of them were point mutations: Pro83Gln, Thr118Ile, Tyr205Phe, Ile183Met, Ser189Thr, Ile232Thr, Pro280Leu, and five cases identified 5 variants of mutations or polymorphisms, socalled codon-synonyms, which do not lead to noticeable violations of functions: Leu150Leu, Leu204Leu, Thr203Thr, Leu204Leu, Pro299Pro. In addition, changes in the position of nucleotides or their dislocations in the intron region of the gene were found in 6 cases. At studying the protein composition of regulatory zones of genes with the detection of various mutations and polymorphisms, the correspondence of Pro83Gln, Pro83Pro, Gln57Gln, Gln63Gln proteins to the first domain of the FCGRIIC protein was found, and the mutations and polymorphisms that corresponded to the second domain of the FCGRIIC protein were Ile183Met, Ser189Thr, Tyr205Phe, Gln57Gln, Gln63Gln, Leu150Leu, Thr203Thr ve Leu204Leu. In addition, in the main group of patients with Hashimoto thyroiditis, there was a high incidence of the mutant alleles of the FCGRIIC gene (90% mutant alleles), whereas in the control group of healthy subjects, the indices were significantly lower (70% mutant alleles). Conclusion. The study of various mutations and polymorphisms were identified according to protein Pro83Gln, Pro83Pro, Gln57Gln, Gln63Gln first FCGRIIC domain of the protein, and mutations and polymorphisms, which correspond to the second domain of the protein FCGRIIC were: Ile183Met, Ser189Thr, Tyr205Phe, Gln57Gln, Gln63Gln, Leu150Leu, Thr203Thr ve Leu204Leu. In addition, in the main group of patients with Hashimoto thyroiditis, a high rate of occurrence of mutant alleles of the FCGRIIC gene (90% mutant alleles) was observed, whereas in the control group of practically healthy individuals, the rates were significantly lower (70% mutant alleles).
