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Reviewed January 2013
What is the official name of the SMAD4 gene?
The official name of this gene is “SMAD family member 4.”
SMAD4 is the gene's official symbol. The SMAD4 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 SMAD4 gene?
The SMAD4 gene provides instructions for making a protein involved in transmitting chemical signals from the cell surface to the nucleus. This signaling pathway, called the transforming growth factor beta (TGF-β) pathway, allows the environment outside the cell to affect how the cell produces other proteins. The signaling process begins when a TGF-β protein attaches (binds) to a receptor on the cell surface, which activates a group of related SMAD proteins. The SMAD proteins bind to the SMAD4 protein and form a protein complex, which then moves to the cell nucleus. In the nucleus, the SMAD protein complex binds to specific areas of DNA where it controls the activity of particular genes and regulates cell growth and division (proliferation).
By controlling gene activity and regulating cell proliferation, the SMAD4 protein serves both as a transcription factor and as a tumor suppressor. Transcription factors help control the activity of particular genes, and tumor suppressors keep cells from growing and dividing too fast or in an uncontrolled way.
Does the SMAD4 gene share characteristics with other genes?
The SMAD4 gene belongs to a family of genes called SMAD (SMAD, mothers against DPP homologs).
A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.
How are changes in the SMAD4 gene related to health conditions?
Where is the SMAD4 gene located?
Cytogenetic Location: 18q21.1
Molecular Location on chromosome 18: base pairs 51,030,213 to 51,085,042
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The SMAD4 gene is located on the long (q) arm of chromosome 18 at position 21.1.
More precisely, the SMAD4 gene is located from base pair 51,030,213 to base pair 51,085,042 on chromosome 18.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about SMAD4?
You and your healthcare professional may find the following resources about SMAD4 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 SMAD4 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 SMAD4?
amino acid ; aneurysm ; aorta ; aortic dissection ; arteries ; benign ; cell ; cell nucleus ; cell proliferation ; colon ; dilation ; disability ; DNA ; gene ; growth factor ; hereditary ; inherited ; isoleucine ; juvenile ; mitral valve ; nucleus ; pancreas ; polyp ; polyposis ; proliferate ; proliferation ; protein ; receptor ; short stature ; stature ; syndrome ; telangiectasia ; transcription ; transcription factor ; tumor ; veins
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (17 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.