HLA-C and ankylosing spondylitis: Some of these genes have been reported to be mutated in diseases related to the immune system, e.g. HLA-DMA: rheumatoid arthritis and lupus, HLA-C: psoriasis and HIV, HLA-B: ankylosing spondylitis (arthritis of the spine) and IRF8 and HLA-DPB1: immune deficiencies (www.genecards.org).