Reviewed December 2007
What is the official name of the SOS1 gene?
The official name of this gene is “son of sevenless homolog 1 (Drosophila).”
SOS1 is the gene's official symbol. The SOS1 gene is also known by other names, listed below.
What is the normal function of the SOS1 gene?
The SOS1 gene provides instructions for making a protein that is involved in pathways within cells that control growth and development. Normally, this protein regulates another protein, called Ras, that stimulates cells to grow and divide. This regulation tightly controls the growth of cells and tissues, and is especially important for proper embryonic development.
How are changes in the SOS1 gene related to health conditions?
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Noonan syndrome - caused by mutations in the SOS1 gene
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More than 20 mutations causing Noonan syndrome have been identified in the SOS1 gene. These mutations change one protein building block (amino acid) in the SOS1 protein. These changes are believed to cause the protein to be continuously active, rather than switching on and off in response to other cellular proteins. The constant activation disrupts the regulation of systems that control cell functions such as growth and division. Researchers believe that increased SOS1 protein activation leading to defective cell movement and differentiation (the process by which cells mature to carry out specific functions) could play a role in the signs and symptoms of Noonan syndrome such as short stature and facial abnormalities.
- other disorders - caused by mutations in the SOS1 gene
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Mutations in the SOS1 gene can also cause hereditary gingival fibromatosis type 1. This disorder is characterized by a slowly progressive overgrowth of the tissue of the gums (gingiva). Too much of this tissue can impair teeth from pushing through the gums, which can cause difficulties in speech and chewing food. So far only one mutation in the SOS1 gene has been shown to cause hereditary gingival fibromatosis type 1. This mutation is an addition of a single building block of DNA (nucleotide) which disrupts the gene's instructions and causes a shortened protein to be made. Unlike the normal SOS1 protein, the shortened protein is permanently active. Instead of triggering cell growth in response to particular signals from outside the cell, the overactive protein directs cells to grow and divide constantly. It is unclear why the overgrowth of tissue is seen only in the gums.
Where is the SOS1 gene located?
Cytogenetic Location: 2p22-p21
Molecular Location on chromosome 2: base pairs 39,066,468 to 39,201,066
The SOS1 gene is located on the short (p) arm of chromosome 2 between positions 22 and 21.
More precisely, the SOS1 gene is located from base pair 39,066,468 to base pair 39,201,066 on chromosome 2.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about SOS1?
You and your healthcare professional may find the following resources about SOS1 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
- PubMed
- Recent literature
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OMIM - Genetic disorder catalog (3 links)
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What other names do people use for the SOS1 gene or gene products?
- alternate SOS1
- GF1
- GGF1
- GINGF
- gingival fibromatosis
- gingival fibromatosis, hereditary, 1
- HGF
- son of sevenless homolog 1
- SOS1_HUMAN
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 SOS1?
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.