Examining the paired TCR α- and β-chains of single cell-sorted IGRP265-273-specific CD8+ T cells, we identified the CDR3 motif SGGSNYKLTF in the TCR α-chain of the dominant clonotypes of patients T1D-1 (299 cells), T1D-2 (5 cells), and T1D-3 (20 cells), and in a further 60 of 94 patient derived IGRP265-273-specific CD8+ T cells for which we obtained TCR α- and β-chain information. Here, CD8A is linked to type 1 diabetes mellitus.