There is an enrichment of HLA loci within Qatari patients and controls and indicates an association of -DQA1*03:01:01G (OR = 2.46, p value = 0.011) and -DQB1*03:02:01G (OR = 2.43, p value = 0.022) with type 1 diabetes mellitus in Qatar (see Supplementary Table 2). Here, HLA-DQA2 is linked to diabetes mellitus.