CDKN2A

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What is the official name of the CDKN2A gene?

The official name of this gene is “cyclin-dependent kinase inhibitor 2A.”

CDKN2A is the gene's official symbol. The CDKN2A 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 CDKN2A gene?

The CDKN2A gene provides instructions for making several proteins. The most well-studied are the p16(INK4a) and the p14(ARF) proteins. Both function as tumor suppressors, which means they keep cells from growing and dividing too rapidly or in an uncontrolled way.

The p16(INK4a) protein attaches (binds) to two other proteins called CDK4 and CDK6. These proteins help regulate the cell cycle, which is the cell's way of replicating itself in an organized, step-by-step fashion. CDK4 and CDK6 normally stimulate the cell to continue through the cycle and divide. However, binding of p16(INK4a) blocks CDK4's or CDK6's ability to stimulate cell cycle progression. In this way, p16(INK4a) controls cell growth and division.

The p14(ARF) protein protects a different protein called p53 from being broken down. The p53 protein is an important tumor suppressor that is essential for regulating cell division and self-destruction (apoptosis). By protecting p53, p14(ARF) also helps prevent tumor formation.

How are changes in the CDKN2A gene related to health conditions?

head and neck squamous cell carcinoma - associated with the CDKN2A gene: Mutations in the CDKN2A gene are found in up to one-quarter of head and neck squamous cell carcinomas (HNSCC). This type of cancerous tumor occurs in the moist lining of the mouth, nose, and throat. CDKN2A gene mutations associated with this condition are acquired during a person's lifetime and are found only in tumor cells; these changes are known as somatic mutations. Most of these mutations lead to production of little or no functional p16(INK4a) protein. Without p16(INK4a) to regulate cell growth and division, cells can continue to grow and divide without control, which can lead to tumor formation.
A different type of alteration involving the CDKN2A gene can result in reduced amounts of the p16(INK4a) or p14(ARF) protein. This alteration, known as promoter hypermethylation, turns off the production of p16(INK4a) or p14(ARF). Without one of these tumor suppressors, cells can grow and divide unchecked, leading to the development of cancer.
other cancers - associated with the CDKN2A gene: Mutations affecting the CDKN2A gene are associated with other cancers, including a type of skin cancer called melanoma, breast cancer, lung cancer, and pancreatic cancer. The mutations associated with these cancers are typically inherited (called germline mutations) and are found in all cells in the body. In some families, CDKN2A gene mutations are associated with development of only one type of cancer. In other families, mutations can lead to a cancer predisposition syndrome, which increases the risk of developing multiple types of cancer.CDKN2A gene mutations involved in cancer impair production of functional p16(INK4a) or, less commonly, p14(ARF), which can result in uncontrolled cell growth and tumor formation.

Where is the CDKN2A gene located?

Cytogenetic Location: 9p21

Molecular Location on chromosome 9: base pairs 21,967,751 to 21,994,490

The CDKN2A gene is located on the short (p) arm of chromosome 9 at position 21.

More precisely, the CDKN2A gene is located from base pair 21,967,751 to base pair 21,994,490 on chromosome 9.

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

Where can I find additional information about CDKN2A?

You and your healthcare professional may find the following resources about CDKN2A helpful.

Educational resources - Information pages (2 links)
Genetic Testing Registry - Repository of genetic test information (1 link)

You may also be interested in these resources, which are designed for genetics professionals and researchers.

PubMed - Recent literature
OMIM - Genetic disorder catalog (5 links)
Research Resources - Tools for researchers (4 links)

What other names do people use for the CDKN2A gene or gene products?

ARF
CDK4I
CDK4 inhibitor p16-INK4
CDKN2
cell cycle negative regulator beta
CMM2
cyclin-dependent kinase 4 inhibitor A
cyclin-dependent kinase inhibitor 2A isoform p12
cyclin-dependent kinase inhibitor 2A isoform p14ARF
cyclin-dependent kinase inhibitor 2A isoform p16gamma
cyclin-dependent kinase inhibitor 2A isoform p16INK4a
cyclin-dependent kinase inhibitor 2A (melanoma, p16, inhibits CDK4)
INK4
INK4A
MLM
MTS1
MTS-1
multiple tumor suppressor 1
P14
P14ARF
P16
P16INK4
P16INK4A
P16-INK4A
P19
P19ARF
TP16

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 CDKN2A?

apoptosis ; cancer ; carcinoma ; cell ; cell cycle ; cell division ; gene ; germline ; inherited ; kinase ;melanoma ; pancreatic ; predisposition ; progression ; promoter ; protein ; syndrome ; tumor

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

References (11 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.