PTPRN and idiopathic type 1 diabetes: However, they only checked for anti-GAD, IAA, and ICA.13 Studies from India proved that antibody positivity reaches from 55% when only Anti GAD and IA2 were checked, while it reached up to 96% when all five antibodies against Type-1 diabetes were estimated.9 The reported prevalence of idiopathic Type-1 diabetes (iAb-) is high (30%) in one study14 but remains low (2.2%) only if all five antibodies are estimated.14,15