What other gene mutations are important in hereditary breast cancer?
These mutations affect only some cells in the body.
These mutations affect all the cells of the body.
Verywell / Gary Ferster
How Do Hereditary Gene Mutations Raise Cancer Risk?
Our DNA is a blueprint or code that is used to manufacture proteins.
The abnormal protein is then unable to perform its usual job.
Not all gene mutations raise the risk of cancer, and in fact, most do not.
Several of the genes associated with a higher breast cancer risk aretumor suppressor genes.
The genes BRCA1 and BRCA2 are tumor suppressor genes.
Added to this, usually, several mutations must occur for a cell to become acancer cell.
For some mutations, the risk of breast cancer is very high.
For others, the risk may be increased by only a factor of 1.5.
This is important to understand when talking about possible preventive options.
A 2017 study found that BRCA mutations accounted for only 9% to 29% of hereditary breast cancers.
Variability Within Mutations
Not all people who have the following gene mutations are the same.
In general, there can be hundreds of ways in which these genes are mutated.
With other mutations, the protein may not be produced at all.
In addition, the breast cancers associated with these mutations can differ.
They are also more likely to have a higher tumor grade.
Those who have two copies of the mutated gene have an uncommon autosomal recessive syndrome known as ataxia-telangiectasia.
PALB2
Mutations in the PALB2 gene are also an important cause of hereditary breast cancer.
CHEK2
The CHEK2 gene codes for a protein that is activated when damage occurs to DNA.
It also activates other genes involved in cell repair.
For both men and women, the gene also increases the risk of colon cancer and non-Hodgkin’s lymphoma.
CDH1
Mutations in CDH1 cause a condition known as hereditary gastric cancer syndrome.
Cancers in people who inherit this mutation are more likely to metastasize.
PTEN
Mutations in the PTEN gene are one of the more common tumor suppressor gene mutations.
The gene codes for proteins that regulate cells' growth, and also helps cells stick together.
Mutations in the gene appear to increase the risk of cancer cells breaking off from a tumor and metastasizing.
PTEN is associated with a syndrome called PTEN hamartoma tumor syndrome as well as Cowden syndrome.
Non-cancer related symptoms include large head size (macrocephaly) and the tendency to form benign tumors known ashamartomas.
STK11
Mutations in STK11 are associated with a genetic condition known as Peutz-Jegher syndrome.
STK11 is a tumor suppressor gene involved in cell growth.
TP53
The TP53 gene codes for proteins that halt the growth of abnormal cells.
These mutations are extremely common in cancer, withacquiredmutations in thep53 genebeing found in around 50% of cancers.
Breast cancers associated with the mutation are often HER2 positive and have a high tumor grade.
PMS2, in particular, has been associated with double the risk of breast cancer.
The gene functions as a tumor suppressor gene, coding for a protein that repairs damaged DNA.
Having these tests available, however, raises many questions.
For example, who might have hereditary breast cancer and who should be tested?
What should you do if you test positive for one of these genes?
Ideally, any testing should be done only with the guidance and help of agenetic counselor.
There are two reasons for this.
As noted earlier, some mutations confer a high risk and others a much lower risk.
Fortunately, there are organizations that focus specifically on supporting people in this situation.
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