From BBC News:
Women with a damaged copy of the gene called PALB2 have twice the risk of breast cancer, the Institute of Cancer Research scientists found. They estimate that faulty PALB2 causes about 100 cases of breast cancer in the UK each year. Two damaged copies of the gene also appears to cause a serious blood disorder in children, they report in Nature Genetics. It is PALB2’s job to repair mutant DNA, so people who have a faulty copy of the gene are more likely to accumulate other genetic damage too, leading to problems like cancer.
Professor Nazneen Rahman and her team studied the DNA of 923 women with breast cancer and a family history of the disease, not caused by the known breast cancer genes BRCA1 or BRCA2. Ten of the breast cancer patients had a damaged copy of PALB2, as against none of 1,084 healthy women used as a comparison. Carrying a faulty version of PALB2 more than doubled a woman’s risk of developing breast cancer – taking her lifetime risk from one in nine to about one in five.
More here.