The first thing you need to know about the BRCA gene is that you have it.
Don't panic. Everyone does. In fact, we all have two of them -- the BRCA1 and 2 genes. They are normal genes that "have an important function in the cell. They are involved in repairing DNA damage," explained Dr. Robert Nussbaum, a medical geneticist at UCSF. "When they're functioning normally, they do a good job for us."
The problem is what happens when they don't function normally. We'll get to that in a minute. But first, in our call, Nussbaum gave me a helpful primer in basic genetics.
For starters, we all have two copies of each of the BRCA genes. Men, too. We get one copy from each parent. These genes are "like sentences," Nussbaum said. "They are made up of words." When they're spelled right, all is well.
But "you can have all kinds of misspellings," Nussbaum said. "Red becomes reed. All kinds of things can happen that will alter the meaning of that sentence."