interferon gamma gene polymorphism as a marker of some allergic diseases (allergic skin diseases and allergic conjunctivitis) in a sample of egyptian population

Introduction: Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur to normally harmless environmental substances known as allergens; these reactions are acquired, predictable, and rapid. Allergy is one of four forms of hypersensitivity and is called type I (or immediate) hypersensitivity.Aim: To Analyze the allelic distribution of interferon gamma gene polymorphism 874A>T in some allergic skin diseases and allergic conjunctivitis.Methods: This study included 300 Egyptian individual, divided into 100 patients with allergic skin diseases, 100 patients with allergic conjunctivitis and 100 healthy individual were taken as controls. Eosinophil count was estimated, Total IgE level was measured by ELISA technique, Nuclear DNA extracted from peripheral leukocytes and interferon gamma gene polymorphism 874A>T detected by Amplification Refractory Mutation system (ARMS-PCR).Results: In the Skin allergic group, the (AT) genotype and the (TT) genotype were the most common (both are 45%), while in the Conjunctivitis group and the normal control groups the (TT) genotype was the most common (60% and 90% respectively). Moreover, there was statistically significant difference in the distribution of the IFN-γ genotypes at position 874 among the studied groups as compared all together.Conclusion: The IFN-ɤ gene polymorphism at position +874 increases susceptibility to atopic diseases, and the identification of variants of the IFN-ɤ gene and their role in the development of atopic diseases provides a focus for the development of novel diagnostic and therapeutic strategies.