title: Polymorphism of HLA-B27: 105 subtypes currently known.
abstract: HLA-B27 has a high degree of genetic polymorphism, with 105 known subtypes, named HLA-B*27:01 to HLA-B*27:106, encoded by 132 alleles. The most common subtypes associated with ankylosing spondylitis are HLA-B*27:05 (Caucasians), HLA-B*27:04 (Chinese), and HLA-B*27:02 (Mediterranean populations). For Chinese populations, HLA-B*27:04 is associated with a greater ankylosing spondylitis risk than HLA-B*27:05. Two subtypes, HLA-B27*06 and HLA-B27*09, seem to have no disease association. These differential disease associations of HLA-B27 subtypes, and the recent discovery that ERAP1 is associated with ankylosing spondylitis for patients with HLA-B27, have increased attempts to determine the function of HLA-B27 in disease pathogenesis by studying hemodynamic features of its protein structure, alterations of its peptidome, aberrant peptide handling, and associated molecular events. However, after 40 years we still do not fully know how HLA-B27 predisposes to ankylosing spondylitis and related spondyloarthritis.
authors.affiliation: MetroHealth Medical Center, Division of Rheumatology, Case Western Reserve University School of Medicine, 2500 MetroHealth Drive, Cleveland, OH 44109-1998, USA. mkhan@metrohealth.org
authors.forename: Muhammad Asim
authors.initials: MA
authors.lastname: Khan
mesh_terms: D000483:Alleles; D044466:Asian People / Q000235:genetics; D020022:Genetic Predisposition to Disease; D015796:HLA-B27 Antigen / Q000235:genetics*; D006801:Humans; D011110:Polymorphism, Genetic; D013167:Spondylitis, Ankylosing / Q000235:genetics* / Q000276:immunology; D044465:White People / Q000235:genetics
chemical_list: D015796:HLA-B27 Antigen