Mutations in a gene called XRCC2 have been linked to breast cancer susceptibility after being found in families in which multiple individuals had developed breast cancer. Those families did not have mutations in the genes currently known to confer breast cancer risk.

“We have added to the list of genes that harbor mutations causing breast cancer,” confirmed Sean Tavtigian, PhD, an investigator at Huntsman Cancer Institute at the University of Utah in Salt Lake City and a coprincipal investigator on the XRCC2 research.

A technology known as exome capture massively parallel sequencing, or exome sequencing, allowed Tavtigian and colleagues to identify XRCC2 as a breast cancer susceptibility gene in persons with a family history of breast cancer. Exome sequencing further identified two different types of XRCC2 mutations that occur in breast cancer patients. More research is under way to determine the proportion of breast cancer cases that can be attributed to these rare XRCC2 mutations and the degree of risk conferred by them.

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The study group also noted in their report for The American Journal of Human Genetics (2012;90[4]:734-739) that PARP inhibitors, which are effective against tumors associated with BRCA1 and BRCA2 mutations, may also combat breast cancer in patients with an XRCC2 mutation, as tumor cells with these gene mutations all lie in the same DNA repair pathway.