Association of candidate gene polymorphisms for autoimmune thyroid diseases in patients with familial diffuse toxic goiter and autoimmune thyroiditis

Abstract

Aim : to study the relation polymorphism of some genes of the immune response with familial autoimmune thyroid disease. Materials and methods. 100 patients from 49 families were examined. At least 2 first-degree affected relatives with autoimmune thyroiditis or diffuse toxic goiter were included from each family. 76 persons were included to control group without thyroid pathology and negative history of any thyroid disease in families. Clinical, hormonal, ultra-sound data was collected for each subject. Genotyping ofCTLA4 A49G and PTPN22 C1858T polymorphisms was performed for 70 patients (35 families) with familial autoimmune thyroid disease and for all subjects from the control group. Results. Autoimmune thyroid disease was observed among one generation (siblings) in 11 families (22.5%) and among two generations (parent-child) in 38 families (75.5%). Patients with chronic autoimmune thyroiditis with hypothyroidism in the outcome were dominated – 66%, 34% experienced diffuse toxic goiter. Autoimmune thyroiditis was observed in parent and offspring from 21 families (55%). In the group of siblings autoimmune thyroiditis was diagnosed for both relatives in 6 families (54%). Frequency of genotypes of CTLA4 A49G polymorphism is not differ between patients with familial autoimmune thyroid disease and control group. Carriage of T allele of PTPN22 C1858T polymorphism is associated with the risk of autoimmune thyroid disease developing in a group of female offspring: OR = 3.175; 95% CI 1,423–7,262. These results allow us to recommend to test this polymorphism to identify patients with the risk of autoimmune thyroid diseases in families. Conclusion. Taking into account that DNA testing is one of the most important part of personalized approach in medicine, the current results of molecular genetic study for familial cases of autoimmune thyroid disease creates prerequisites for optimizing the diagnostic pathway of these patients.