The radiation that young women are exposed to during a mammogram may actually put them at significantly higher risk of developing breast cancer, especially if they are genetically predisposed to it, according to a study published Thursday in the BMJ.

Though women are typically only screened for breast cancer with mammograms over the age of 40, some women who carry the BRCA1 or BRCA2 gene, which increases a woman's risk five-fold, begin screening earlier. However, this new research finds that tactic may actually put the women at greater risk of developing cancer.

"BRCA genes help repair DNA damage – damage which can be caused by exposure to radiation like X-rays. Women with faults in these genes are less able to repair damage caused by radiation, so they are at a greater risk of developing breast cancer. It’s important that these women and their doctors are aware of this." a study author Professor Douglas Easton, a Cancer Research UK scientist at the University of Cambridge, said in a press release.

The study, which looked at 2,000 women with these genetic markers in the Netherlands, France and the U.K. between 2006 and 2009, found women under 30 who experienced chest radiation had 43 precent increased risk of developing breast cancer over women who didn't have exposure to chest radiation. Exposure before age 20 increased the risk by 62 percent.

"We believe countries who use mammograms in women under 30 should reconsider their guidelines," one of the study's authors, Anouk Pijpe of the Netherlands Cancer Institute, told the Associated Press.

Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society, told the AP he worries the results of this study will prevent women from seeking screening for cancer. "No one should think that they should never get an X-ray because they have the BRCA1 or 2 gene mutations," he said. "Just be careful that the X-rays you get are really the ones that you need."

[Young women getting mammogram via Shutterstock]