Variants in the genes encoding class I HLA proteins (HLA-A, HLA-B and HLA-C, expressed on all nucleated cells) have been shown to be strongly associated with ankylosing spondylitis (e.g. HLA-B27), Graves’ Disease (e.g. HLA-C*07), Type I diabetes (e.g. B*39) and multiple sclerosis (e.g. C*05)46. Here, HLA-C is linked to type 1 diabetes mellitus.