[ad_1]
Broken emails
Receive alerts and special reports. News and stories that matter, delivered in the morning on weekdays.
Breast cancer is one of the most worrisome diagnoses that a woman can have, and women now know that they can be prevented if they have a very high risk by undergoing genetic testing.
Mutations in dozens of different genes may increase the risk of breast cancer, but the two best-known genes are BRCA1 and BRCA2. Everyone carries these genes. When breast cancer, ovarian cancer or prostate cancer occur in a family, doctors often recommend doing a test to determine if a patient is wearing a risky version of one's dad. Between them.
Now, there are home tests for BRCA1 and BRCA2 common mutations. Some clearly raise the risk of cancer in a woman and she may undergo more regular mammograms or, as the actress Angelie Jolie did, have her breasts removed surgically.
However, many people have mutations called variants of uncertain significance. It is not known if they increase the risk of cancer.
Mutations are errors in the genetic code, represented by the letters A, T, C and G repeated over and over again. Big mistakes in the code mean that the BRCA genes do not work properly and do not correct the damage in the cells that can lead to cancer.
But the BRCA1 gene is 10,000 letters long. Many small mistakes can occur in such a long sequence, and not all of them mean cancer.
How can you tell which ones to do?
Jay Shendure of the University of Washington and his colleagues think they have found a way to say it. They laboriously created one-to-one mutations in a batch of cancer cells that die when they carry mutations that affect the function of a gene.
To do this, they used a precision DNA verification method called CRISPR. They created nearly 4,000 single-letter mutations, one by one, on their cell plates and found that they could predict which mutations might increase the risk of cancer.
They will not be able to say precisely how these errors affect the development of cancer in a living human, but when they compared their results with known mutations causing cancer, they aligned themselves.
The method could be used to help people with so-called variants of uncertain significance if they should be concerned.
"We anticipate that these results will be immediately useful for the clinical interpretation of BRCA1 variants," they wrote in their report, published Wednesday in the journal Nature.
Breast cancer is the second leading cause of cancer in American women after lung cancer. The American Cancer Society says that every year it is diagnosed in 260,000 women and some men and kills about 40,000 people.
About 12% of all women will develop breast cancer in their lifetime.
BRCA mutations are among dozens of other genetic mutations that increase the risk of breast or ovarian cancer. The BRCA1 and BRCA2 genes are DNA repair genes, which detect and correct errors causing cancer elsewhere in the DNA code. When they themselves make mistakes, the repair is not done or it is badly done.
About 55% to 65% of women with a known carcinogenic BRCA1 mutation will develop breast cancer at the age of 70, according to the National Cancer Institute. About 45% of women with defective BRCA2 genes will do so.
This new approach could add to the list of risk mutations and could possibly be used to predict the effects of other genetic mutations, the researchers said.
"If such a variant were present in a family member, would I use this information? Absolutely," Shendure said in a statement.
Source link
