title: Remarkable polymorphism of HLA-B27: an ongoing saga.
abstract: Histocompatibility antigen HLA-B27 is a normal gene that is distributed worldwide with variable prevalence and shows a remarkable association with ankylosing spondylitis and related spondyloarthropathies. The precise biological explanation for this remarkable association remains elusive. HLA-B27 represents a family of closely related proteins encoded by an ever-increasing number of alleles; there are 75 alleles of HLA-B27 known thus far, based on nucleotide sequence differences, but at the translated protein level, there are 62 known subtypes of HLA-B27. Not all subtypes are disease associated. Moreover, existence of a possible hierarchical ranking among some of the subtypes for their disease association has been observed.
authors.affiliation: Division of Rheumatology, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH 44109, USA. mkhan@metrohealth.org
authors.forename: Muhammad Asim
authors.initials: MA
authors.lastname: Khan
mesh_terms: D017668:Age of Onset; D000483:Alleles; D000818:Animals; D004195:Disease Models, Animal; D020022:Genetic Predisposition to Disease; D015796:HLA-B27 Antigen / Q000235:genetics* / Q000266:history; D049673:History, 20th Century; D006801:Humans; D051379:Mice; D011110:Polymorphism, Genetic; D015995:Prevalence; D025242:Spondylarthropathies / Q000453:epidemiology / Q000209:etiology / Q000235:genetics*; D013167:Spondylitis, Ankylosing / Q000453:epidemiology / Q000209:etiology / Q000235:genetics*
chemical_list: D015796:HLA-B27 Antigen