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Reviewed August 2009
What is the official name of the HAL gene?
The official name of this gene is “histidine ammonia-lyase.”
HAL is the gene's official symbol. The HAL 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 HAL gene?
The HAL gene provides instructions for making an enzyme called histidase. Histidase breaks down the amino acid histidine, a building block of most proteins. Histidase is active (expressed) primarily in the liver and the skin. This enzyme breaks down histidine to a molecule called urocanic acid. In the liver, urocanic acid is broken down to form another amino acid called glutamic acid. In the skin, urocanic acid is involved in the response to ultraviolet (UV) light.
How are changes in the HAL gene related to health conditions?
Where is the HAL gene located?
Cytogenetic Location: 12q22-q24.1
Molecular Location on chromosome 12: base pairs 95,972,662 to 95,996,365
The HAL gene is located on the long (q) arm of chromosome 12 between positions 22 and 24.1.
More precisely, the HAL gene is located from base pair 95,972,662 to base pair 95,996,365 on chromosome 12.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about HAL?
You and your healthcare professional may find the following resources about HAL 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 HAL 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 HAL?
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (5 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.