The T1D GRS predicted progression to insulin use at five years, but only in GAD-positive participants: probability of insulin use (95% CI): 47.9% for high T1D GRS (35.0%, 62.78%) vs. 27.6% for medium T1D GRS (20.5%, 36.5%) vs. 17.6% for low-risk T1D GRS (11.2%, 27.2%); P = 0.001 [39]. Here, GAD1 is linked to type 1 diabetes mellitus.