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Reviewed May 2010
What is the official name of the XPA gene?
The official name of this gene is “xeroderma pigmentosum, complementation group A.”
XPA is the gene's official symbol. The XPA 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 XPA gene?
The XPA gene provides instructions for making a protein that is involved in repairing damaged DNA. DNA can be damaged by ultraviolet (UV) rays from the sun and by toxic chemicals, radiation, and unstable molecules called free radicals.
DNA damage occurs frequently, but normal cells are usually able to fix it before it can cause problems. One of the major mechanisms that cells use to fix DNA is known as nucleotide excision repair (NER). As part of this repair mechanism, the XPA protein helps verify DNA damage and stabilize the DNA as it is repaired. The XPA protein attaches (binds) to areas of damaged DNA, where it interacts with many other proteins as part of a large complex. Proteins in this complex unwind the section of DNA where the damage has occurred, snip out (excise) the abnormal section, and replace the damaged area with the correct DNA.
How are changes in the XPA gene related to health conditions?
Where is the XPA gene located?
Cytogenetic Location: 9q22.3
Molecular Location on chromosome 9: base pairs 100,437,190 to 100,459,690
The XPA gene is located on the long (q) arm of chromosome 9 at position 22.3.
More precisely, the XPA gene is located from base pair 100,437,190 to base pair 100,459,690 on chromosome 9.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about XPA?
You and your healthcare professional may find the following resources about XPA 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 XPA 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 XPA?
cancer ; cell ; difficulty swallowing ; dimer ; DNA ; DNA damage ; DNA repair ; free radicals ; gene ; genome ; mutation ; NER ; nervous system ; neurological ; nucleotide ; nucleotide excision repair ; population ; protein ; radiation ; toxic ; transcription ; UV rays
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (7 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.