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Reviewed April 2014

What is the official name of the CTC1 gene?

The official name of this gene is “CTS telomere maintenance complex component 1.”

CTC1 is the gene's official symbol. The CTC1 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 CTC1 gene?

The CTC1 gene provides instructions for making a protein that plays an important role in structures known as telomeres, which are found at the ends of chromosomes. Telomeres are short, repetitive segments of DNA that help 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).

The CTC1 protein works as part of a group of proteins known as the CST complex, which is involved in the maintenance of telomeres. This complex is part of the special machinery that some cells use to copy (replicate) telomeres so they do not become too short as cells divide. Studies suggest that the CTC1 protein may also have roles in DNA replication unrelated to telomeres, but these functions are not well understood.

How are changes in the CTC1 gene related to health conditions?

Coats plus syndrome - caused by mutations in the CTC1 gene

At least 20 mutations in the CTC1 gene have been identified in people with Coats plus syndrome. This disorder is characterized by an eye condition called Coats disease plus abnormalities of the brain, bones, gastrointestinal system, and other parts of the body.

Most people with Coats plus syndrome have a mutation in one copy of the CTC1 gene in each cell that eliminates the function of the CTC1 protein and a mutation in the other copy of the gene that reduces but does not eliminate the protein's function. This combination of mutations leaves only a small amount of functional CTC1 protein available to work as part of the CST complex. The resulting impairment of this complex affects the replication of telomeres, although the effect on telomere structure and function is unclear. Some studies have found that people with CTC1 gene mutations have abnormally short telomeres, while other studies have found no change in telomere length. Researchers are working to determine how telomeres are different in people with CTC1 gene mutations and how these changes could underlie the varied signs and symptoms of Coats plus syndrome.

Genetics Home Reference provides information about dyskeratosis congenita, which is also associated with changes in the CTC1 gene.

Where is the CTC1 gene located?

Cytogenetic Location: 17p13.1

Molecular Location on chromosome 17: base pairs 8,224,821 to 8,248,095

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBIThis link leads to a site outside Genetics Home Reference.)

The CTC1 gene is located on the short (p) arm of chromosome 17 at position 13.1.

The CTC1 gene is located on the short (p) arm of chromosome 17 at position 13.1.

More precisely, the CTC1 gene is located from base pair 8,224,821 to base pair 8,248,095 on chromosome 17.

See How do geneticists indicate the location of a gene? in the Handbook.

Where can I find additional information about CTC1?

You and your healthcare professional may find the following resources about CTC1 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 CTC1 gene or gene products?

  • AAF132
  • AAF-132
  • alpha accessory factor 132
  • C17orf68
  • conserved telomere capping protein 1
  • CST complex subunit CTC1
  • FLJ22170
  • HBV DNAPTP1-transactivated protein B
  • RP11-849F2.8
  • tmp494178

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 CTC1?

apoptosis ; cell ; DNA ; DNA replication ; gastrointestinal ; gene ; mutation ; protein ; subunit ; syndrome ; telomere

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References (6 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.

Reviewed: April 2014
Published: February 8, 2016