Nomenclature for Factors of the HLA System

Nomenclature of HLA Alleles

Update to HLA Nomenclature, 2009 - Please click here for further details.

Early in their study it was recognised that the genes encoding the HLA molecules were highly polymorphic and that there was a need for a systematic nomenclature. The HLA complex is located within the 6p21.3 region on the short arm of human chromosome 6 and contains more than 220 genes of diverse function. Many of the genes encode proteins of the immune system. The naming of new HLA genes and allele sequences and their quality control is the responsibility of the WHO Nomenclature Committee for Factors of the HLA System, which first met in 1968, and laid down the criteria for successive meetings. This committee meets regularly to discuss issues of nomenclature and has published 16 major reports documenting firstly the HLA antigens and more recently the genes and alleles. The standardisation of HLA antigenic specifications has been controlled by the exchange of typing reagents and cells in the International Histocompatibility Workshops.

Since 1989 when a large number of HLA allele sequences were first analysed and named, the job of curating and maintaining a database of sequences has been of prime importance. The dissemination of new allele names and sequences is of paramount importance in the clinical setting and through the work of the HLA Informatics Group and in collaboration with the European Bioinformatics Institute, we are able to provide public access to this data through the web sites http://www.ebi.ac.uk/imgt/hla/ and here at http://hla.alleles.org. The IMGT/HLA Database collects both new and confirmatory sequences, which are then expertly analysed and curated before been named by the Nomenclature Committee. The resulting sequences are then included in the tools and files made available from both the IMGT/HLA Database and this site. These regular updates ensure that new and confirmatory sequences are dispersed to the HLA community, and the wider research and clinical communities.

Steven GE Marsh, BSc PhD ARCS
Chair, WHO Nomenclature Committee for Factors of the HLA System

Graph of HLA Alleles and Antigens named by year

Graph showing numbers of alleles named by year from 1968 to January 2010.
(A higher resolution version is available from here)

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