Cytotoxic T lymphocyte antigen-4 Ala17 polymorphism is a genetic marker of autoimmune adrenal insufficiency: Italian association study and meta-analysis of European studies

ObjectiveCytotoxic T lymphocyte antigen-4 (CTLA4) gene polymorphism has been associated with human autoimmune diseases, but discordant data are available on its association with autoimmune Addison's disease (AAD). We tested the human leukocyte antigen (HLA)-independent association of CTLA4+49 (A/G) (Ala 17) and/or CTLA4 CT60 (A/G) polymorphism with AAD.DesignDNA samples from 180 AAD patients and 394 healthy control subjects from continental Italy were analyzed, and association statistical analyses and meta-analysis of published studies were performed.MethodsTaqMan minor groove binder chemistry assays and PCR fragment length polymorphism assays were used.ResultsFrequency of allele G of CTLA4+49 was significantly increased among AAD patients (40% alleles) than among healthy controls (27% alleles; P