IA-2, a R8 receptor protein tyrosine phosphatase, is one of the major autoantigens in type 1 diabetes. Autoantibodies against IA-2 have been detected in large numbers newly diagnosed patients with type 1 diabetes and appear to identify a subgroup of prediabetic subjects who rapidly progress to type 1 diabetes, however, IA-2 polymorphisms do not appear to be associated with type 1 diabetes. Three alternative spliced variants of IA-2 have been documented and alternative splicing of IA-2 gene has been suggested to be a permissive genetic mechanism for autoimmunity against the IA-2 type 1 diabetes autoantigen.Synonyms: ICA3, ICA512, Islet cell antigen 512, PTP IA-2, R-PTP-N, Receptor-type tyrosine-protein phosphatase-like N