Researchers analysed data from around 10,000 US families impacted by ovarian cancer and discovered that women can inherit the disease through their father’s X chromosome.
Women born to fathers whose mother had been affected by ovarian cancer were found to be twice as likely to develop the disease, compared to those who inherited it from their mother’s side of the family. They also had an earlier age-of-onset.
This cancer susceptibility gene, called MAGEC3, is entirely different from the BRCA1 and BRCA2 mutations long associated with the disease. It was was also found to be associated with higher rates of prostate cancer in fathers and sons.
Lead author Kevin Eng from the Roswell Park Comprehensive Cancer Centre told the BBC: "What we have to do next is make sure we have the right gene by sequencing more families. This finding has sparked a lot of discussion within our group about how to find these X-linked families.
"It's an all-or-none kind of pattern: A family with three daughters who all have ovarian cancer is more likely to be driven by inherited X mutations than by BRCA mutations."
The researchers say that further studies are required but the finding could have a significant impact on ovarian cancer prevention.