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Reviewed July 2010
What is the official name of the HLA-B gene?
The official name of this gene is “major histocompatibility complex, class I, B.”
HLA-B is the gene's official symbol. The HLA-B gene is also known by other names, listed below.
Read more about gene names and symbols on the About page.
What is the normal function of the HLA-B gene?
The HLA-B gene provides instructions for making a protein that plays a critical role in the immune system. HLA-B is part of a family of genes called the human leukocyte antigen (HLA) complex. The HLA complex helps the immune system distinguish the body's own proteins from proteins made by foreign invaders such as viruses and bacteria.
HLA is the human version of the major histocompatibility complex (MHC), a gene family that occurs in many species. Genes in this complex are categorized into three basic groups: class I, class II, and class III. In humans, the HLA-B gene and two related genes, HLA-A and HLA-C, are the main genes in MHC class I.
MHC class I genes provide instructions for making proteins that are present on the surface of almost all cells. On the cell surface, these proteins are bound to protein fragments (peptides) that have been exported from within the cell. MHC class I proteins display these peptides to the immune system. If the immune system recognizes the peptides as foreign (such as viral or bacterial peptides), it responds by triggering the infected cell to self-destruct.
The HLA-B gene has many possible variations, allowing each person's immune system to react to a wide range of foreign invaders. Hundreds of versions (alleles) of the HLA-B gene are known, each of which is given a particular number (such as HLA-B27). Closely related alleles are categorized together; for example, more than 60 very similar alleles are subtypes of HLA-B27. These subtypes are designated as HLA-B*2701 to HLA-B*2763.
Does the HLA-B gene share characteristics with other genes?
The HLA-B gene belongs to a family of genes called HLA (histocompatibility complex genes).
A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.
How are changes in the HLA-B gene related to health conditions?
Genetics Home Reference provides information about these additional conditions, which are also associated with changes in the HLA-B gene:
Where is the HLA-B gene located?
Cytogenetic Location: 6p21.3
Molecular Location on chromosome 6: base pairs 31,321,648 to 31,324,988
The HLA-B gene is located on the short (p) arm of chromosome 6 at position 21.3.
More precisely, the HLA-B gene is located from base pair 31,321,648 to base pair 31,324,988 on chromosome 6.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about HLA-B?
You and your healthcare professional may find the following resources about HLA-B helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
What other names do people use for the HLA-B gene or gene products?
See How are genetic conditions and genes named? in the Handbook.
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding HLA-B?
acquired immunodeficiency syndrome ; AIDS ; allopurinol ; arthritis ; bacteria ; carbamazepine ; cell ; chronic ; class ; cutaneous ; fever ; gastrointestinal ; gene ; gout ; HIV ; HLA ; idiopathic ; immune system ; immunodeficiency ; infection ; inflammation ; joint ; joint inflammation ; juvenile ; leukocyte ; malaria ; MHC ; population ; progression ; protein ; psoriasis ; sensitivity ; spondylitis ; stomach ; syndrome ; uric acid ; virus
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (25 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.