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Reviewed May 2012
What is the official name of the APP gene?
The official name of this gene is “amyloid beta (A4) precursor protein.”
APP is the gene's official symbol. The APP 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 APP gene?
The APP gene provides instructions for making a protein called amyloid precursor protein. This protein is found in many tissues and organs, including the brain and spinal cord (central nervous system). Little is known about the function of amyloid precursor protein. Researchers speculate that it may bind to other proteins on the surface of cells or help cells attach to one another. Studies suggest that in the brain, it helps direct the movement (migration) of nerve cells (neurons) during early development.
Amyloid precursor protein is cut by enzymes to create smaller fragments (peptides), some of which are released outside the cell. Two of these fragments are called soluble amyloid precursor protein (sAPP) and amyloid beta (β) peptide. Recent evidence suggests that sAPP has growth-promoting properties and may play a role in the formation of nerve cells (neurons) in the brain both before and after birth. The sAPP peptide may also control the function of certain other proteins by turning off (inhibiting) their activity. Amyloid β peptide is likely involved in the ability of neurons to change and adapt over time (plasticity). Other functions of sAPP and amyloid β peptide are under investigation.
Does the APP gene share characteristics with other genes?
The APP gene belongs to a family of genes called endogenous ligands (endogenous ligands).
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 APP gene related to health conditions?
Where is the APP gene located?
Cytogenetic Location: 21q21.3
Molecular Location on chromosome 21: base pairs 25,880,549 to 26,171,127
The APP gene is located on the long (q) arm of chromosome 21 at position 21.3.
More precisely, the APP gene is located from base pair 25,880,549 to base pair 26,171,127 on chromosome 21.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about APP?
You and your healthcare professional may find the following resources about APP 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 APP 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 APP?
acids ; aggregate ; alanine ; amino acid ; amyloid ; amyloid beta-protein ; asparagine ; aspartic acid ; cell ; central nervous system ; dementia ; elastic ; gene ; glutamic acid ; glutamine ; glycine ; hemorrhagic stroke ; hereditary ; isoleucine ; leucine ; lysine ; mutation ; nervous system ; neurological ; peptide ; plasticity ; precursor ; protease ; protein ; protein sequence ; soluble ; toxic ; valine ; vascular
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (19 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.