We tested the difference in effect size in type 1 diabetes diagnosed <7 years compared to >13 years within genome-wide significant loci (excluding MHC region due to high LD between HLA loci) and in 67 SNPs present in the T1D-GRS2x model (to determine if known type 1 diabetes loci have significant heterogeneity despite not reaching genome-wide significance). Here, HLA-C is linked to type 1 diabetes mellitus.