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Reviewed December 2015
What is the official name of the MASP1 gene?
The official name of this gene is “mannan-binding lectin serine peptidase 1 (C4/C2 activating component of Ra-reactive factor).”
MASP1 is the gene's official symbol. The MASP1 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 MASP1 gene?
The MASP1 gene provides instructions for making proteins that are involved in a series of reactions called the lectin complement pathway. This pathway is thought to help direct the movement (migration) of cells during early development before birth to form the organs and systems of the body. It appears to be particularly important in directing the migration of neural crest cells, which give rise to various tissues including many tissues in the face and skull, the glands that produce hormones (endocrine glands), and portions of the nervous system. After birth, the lectin complement pathway is involved in the immune system.
Three different proteins, MASP-1, MASP-3, and MAp44 can be produced from the MASP1 gene, depending on how the gene's instructions are pieced together.
Does the MASP1 gene share characteristics with other genes?
The MASP1 gene belongs to a family of genes called PRSS (serine peptidases).
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 MASP1 gene related to health conditions?
- 3MC syndrome - caused by mutations in the MASP1 gene
- At least 10 MASP1 gene mutations have been identified in people with 3MC syndrome, a disorder characterized by unusual facial features and a variety of problems affecting other tissues and organs of the body. The MASP1 gene mutations that cause 3MC syndrome affect the MASP-3 protein; some affect the MASP-1 protein in addition to MASP-3. The protein changes result in faulty control of cell migration in embryonic development, leading to the various abnormalities that occur in this disorder. Researchers suggest that the existence of parallel pathways in the immune system that can compensate for problems in the lectin complement pathway account for the absence of immune system problems in 3MC syndrome.
Where is the MASP1 gene located?
Cytogenetic Location: 3q27-q28
Molecular Location on chromosome 3: base pairs 187,216,085 to 187,292,022
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The MASP1 gene is located on the long (q) arm of chromosome 3 between positions 27 and 28.
More precisely, the MASP1 gene is located from base pair 187,216,085 to base pair 187,292,022 on chromosome 3.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about MASP1?
You and your healthcare professional may find the following resources about MASP1 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 MASP1 gene or gene products?
- complement-activating component of Ra-reactive factor
- complement factor MASP-3
- mannose-binding lectin-associated serine protease 1
- mannose-binding protein-associated serine protease
- Ra-reactive factor serine protease p100
- serine protease 5
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.
- What is DNA?
- What is a gene?
- How do genes direct the production of proteins?
- How can gene mutations affect health and development?
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding MASP1?
cell ; embryonic ; gene ; immune system ; mannose ; nervous system ; neural crest ; protease ;protein ; serine ; syndrome
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (7 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