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Reviewed March 2014
What is the official name of the TERT gene?
The official name of this gene is “telomerase reverse transcriptase.”
TERT is the gene's official symbol. The TERT 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 TERT gene?
The TERT gene provides instructions for making one component of an enzyme called telomerase. Telomerase maintains structures called telomeres, which are composed of repeated segments of DNA found at the ends of chromosomes. Telomeres protect chromosomes from abnormally sticking together or breaking down (degrading). In most cells, telomeres become progressively shorter as the cell divides. After a certain number of cell divisions, the telomeres become so short that they trigger the cell to stop dividing or to self-destruct (undergo apoptosis). Telomerase counteracts the shortening of telomeres by adding small repeated segments of DNA to the ends of chromosomes each time the cell divides.
In most types of cells, telomerase is either undetectable or active at very low levels. However, telomerase is highly active in cells that divide rapidly, such as cells that line the lungs and gastrointestinal tract, cells in bone marrow, and cells of the developing fetus. Telomerase allows these cells to divide many times without becoming damaged or undergoing apoptosis. Telomerase is also abnormally active in most cancer cells, which grow and divide without control or order.
The telomerase enzyme consists of two major components that work together. The component produced from the TERT gene is known as hTERT. The other component is produced from a gene called TERC and is known as hTR. The hTR component provides a template for creating the repeated sequence of DNA that telomerase adds to the ends of chromosomes. The hTERT component then adds the new DNA segment to chromosome ends.
How are changes in the TERT gene related to health conditions?
Genetics Home Reference provides information about breast cancer, which is also associated with changes in the TERT gene.
Where is the TERT gene located?
Cytogenetic Location: 5p15.33
Molecular Location on chromosome 5: base pairs 1,253,167 to 1,295,047
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The TERT gene is located on the short (p) arm of chromosome 5 at position 15.33.
More precisely, the TERT gene is located from base pair 1,253,167 to base pair 1,295,047 on chromosome 5.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about TERT?
You and your healthcare professional may find the following resources about TERT 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 TERT 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 TERT?
acids ; acute ; acute myeloid leukemia ; anemia ; aplastic anemia ; apoptosis ; bone marrow ; cancer ; catalytic ; cell ; chromosome ; DNA ; DNA damage ; enzyme ; familial ; fetus ; fibrosis ; gastrointestinal ; gene ; idiopathic ; leukemia ; leukoplakia ; melanoma ; mucosa ; myeloid ; pigmentation ; protein ; pulmonary ; risk factors ; sporadic ; subunit ; telomere ; template
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (15 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.