New gene linked to major breast cancer risk

Washington: A new study has revealed that another gene associated with major breast cancer risk.

According to the study, women mutations in the PALB2 gene have on average a one in three chance of developing breast cancer by the age of seventy.

In a study run through the international PALB2 Interest Group, a team of researchers from 17 centres in eight countries led by the University of Cambridge analysed data from 154 families without BRCA1 or BRCA2 mutations, which included 362 family members with PALB2 gene mutations.

The scientists found that women who carried rare mutations in PALB2 were found to have on average a 35% chance of developing breast cancer by the age of seventy. However, the risks were highly dependent on family history of breast cancer where carriers with more relatives affected by breast cancer, were at higher risk.

PALB2 is known to interact with both the BRCA1 and BRCA2, the genes which have been linked to the disease, and was first linked with breast cancer in 2007. As is the case for women who carry mutations in BRCA1 or BRCA2, women with PALB2 mutations who were born more recently tended to be at a higher risk of developing breast cancer than those born earlier.

Marc Tischkowitz from the Department of Medical Genetics at the University of Cambridge, who led the study, said that since the BRCA1 and BRCA2 mutations were discovered in the mid-90s, no other genes of similar importance have been found and the consensus in the scientific community if more exist they would have found them by now. PALB2 is a potential candidate to be 'BRCA3'. As mutations in this gene are uncommon, obtaining accurate risk figures is only possible through large international collaborations like this.

The study was published in the New England Journal of Medicine.