People inherit two copies of each gene - one from each parent - an evolutionary fail-safe to ensure survival even when one of them doesn't function.
- By MARK GAIGE
For cancer-suppressor genes like BRCA1, researchers have long hypothesized that a single healthy copy could still guard against tumor development. Yet women with one harmful BRCA1 mutation are far more likely to develop breast cancer - a risk traditionally explained by a second mutation that arises later in life, damages the healthy copy of the gene, and triggers disease.
But does this two-hit model tell the whole story?
Likely not, according to the findings of a new study led by scientists at Harvard Medical School.
The research, published Nov. 11 in Nature Genetics, shows that even in the absence of a second mutational hit, a single faulty copy of BRCA1 renders breast cells more vulnerable to cancer and is sufficient to ignite tumor growth.
