| Abstract: | Graves’ disease is an organ‐specific autoimmune disease that has a female predominance. It is probably the result of a complex interaction of genetic and environmental factors. This disease is characterized by immune system activation, evidenced by elevated serum thyroid‐specific autoantibodies and lymphocytic infiltration of the target organ (the thyroid gland), associated with raised levels of circulating activated T lymphocytes. Several reports have demonstrated genetic linkage and association between the genetic markers of the CTLA‐4 gene on chromosome 2q33 and Graves’ disease. In order to confirm this association in the Lebanese population, a bi‐allelic A/G polymorphism at position 49 of CTLA‐4 exon 1 was studied in 34 patients with Graves’ disease, and in 38 healthy individuals, using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analysis. The results showed a significant increase in allele and genotype frequencies in patients with Graves’ disease compared to controls. This suggests that the CTLA‐4 gene might play a role in the development of Graves’ disease in the Lebanese population. |
