While BRCA genes are known to be a huge risk factor in developing breast cancer, they’re not the only type. Scientists have found a gene that is less common but can put women at just as much of a risk.
If there are mutations in the PALB2 gene, a woman is nine times more likely to develop breast cancer, according to a study published in New England Journal of Medicine.
Dr. Jeffrey Weitzel, a genetics expert at City of Hope Cancer Center in Duarte, California, said that scientists knew about five to 10 percent of breast cancers were due to the BRCA1 and BRCA2 genes. They have thought other genes could be just as risky, but were not sure how much they raised the risk.
The PALB2 is likely the most dangerous — after the BRCA genes — as far as developing breast cancer goes. The study looked at 362 members of 154 families with the PALB2 mutation. They found that having a PALB2 gene mutation seemed to indicate that women had a 14 percent chance of developing breast cancer by age 50 and a 35 percent chance by age 70. Women had an even greater risk if they had two or more family members who had the disease.
The PALB2 gene teams up with BRCA2 to suppress tumors — but when mutated it can encourage cancer.
How common is the mutation? That’s probably not known, Weitzel said, but it’s “probably more than we thought because people just weren’t testing for it.”
Men who have the PALB2 gene mutation aren’t exempt — they have a breast cancer risk that is eight times greater than men in the general population.