Ankylosing spondylitis is a common, highly heritable inflammatory arthritis affecting primarily the spine and pelvis. In addition to HLA-B*27 alleles, 12 loci have previously been identified that are associated with ankylosing spondylitis in populations of European ancestry, and 2 associated loci have been identified in Asians. In this study, we used the Illumina Immunochip microarray to perform a case-control association study involving 10,619 individuals with ankylosing spondylitis (cases) and 15,145 controls. We identified 13 new risk loci and 12 additional ankylosing spondylitis-associated haplotypes at 11 loci. Two ankylosing spondylitis-associated regions have now been identified encoding four aminopeptidases that are involved in peptide processing before major histocompatibility complex (MHC) class I presentation. Protective variants at two of these loci are associated both with reduced aminopeptidase function and with MHC class I cell surface expression.
730 - 738
Alleles, Case-Control Studies, DNA Mutational Analysis, Genetic Loci, Genetic Predisposition to Disease, Genome-Wide Association Study, Genotype, Genotyping Techniques, HLA-B27 Antigen, High-Throughput Nucleotide Sequencing, Humans, Immune System Phenomena, Polymorphism, Single Nucleotide, Risk Factors, Spondylitis, Ankylosing