PTPRK and type 1 diabetes mellitus: In contrast to a recent meta-analysis of 15696 cases typed with the ImmunoChip [23] which found strong evidence for association with age at onset in only two genomic regions—the HLA region and the PTPRK / THEMIS region on 6q22.33—we find that several other risk loci for type 1 diabetes are also associated with age at onset.