How Much Does BRCA1 Raise Breast Cancer Risk?
Siddhartha Mukherjee says a BRCA1 mutation is a shove mutation: it puts a person at a ninefold or tenfold risk, above the normal population, of hereditary breast cancer at an early age. He calls BRCA2 a shove mutation as well.
He says the single genes already known still cover only about a third, maybe a fourth, of hereditary breast cancer. The rest, he says, is probably hundreds of genes, each pushing risk by a small percentage. He calls those nudge mutations. He also says the old figure, 5 percent of mutations being hereditary, is no longer 5 percent.