PTPN22 and Alzheimer disease: Further, their pathogenesis is contributed to by the SNPs of several susceptibility non-HLA genes [3,5], including the PTPN22 (protein tyrosine phosphatase non-receptor type 22) C1858T variant encoding for the R620W (rs2476601) Lyp frequently discovered in patients with T1D, AITD, AD and APS2 syndrome [8,9].