GAD1 and type 1 diabetes mellitus: For example, in Sudan, a recent study of clinically diagnosed T1D patients <18 years old who were close to diagnosis (<18 months of diabetes duration) showed that GAD and IA-2 autoantibody positivity rates were 53.5 and 27.2%, respectively, with an overall 69.7% positive for at least one autoantibody (62).