PTPN22 and type 1 diabetes mellitus: SNP variants that showed the strongest positive change with increased islet autoimmunity in our ranking method were linked to PTPN22, INS, SH2B3, ERBB3, RNLS and IL2RA. Variants in these genes were previously associated with the development of autoantibodies, disease development and progression from presenting with autoantibodies to type 1 diabetes onset in at-risk individuals [12, 22–26].