Women who inherit a damaged version of a gene called ATM may have a higher risk of developing breast cancer, according to a study conducted by British researchers.

The new study compared the presence of the damaged ATM gene in breast cancer patients to healthy individuals without breast cancer. Using statistical analysis, researchers determined that women who carry the mutated ATM gene have nearly twice the risk of breast cancer.

ATM is a DNA-repairing gene, similar to the BRCA gene (defects of which are known to be associated with breast cancer). When these genes are faulty, they are unable to effectively repair DNA. The damaged cells can replicate uncontrollably and develop into cancer cells. For this reason, individuals with certain gene mutations have an increased risk of certain cancers.

The study, conducted by scientists at The Institute of Cancer Research, involved 954 women divided into two groups. The first group comprised 433 breast cancer patients with a family history of the disease. These women did not have BRCA1 or BRCA2 gene mutations.

The control group contained 521 healthy women without breast cancer. In the breast cancer patients, researchers found 12 ATM gene mutations compared to only 2 in the healthy group.

According to the American Cancer Society, approximately 5 to 10 percent of breast cancers are associated with inherited genetic mutations. In the past, scientists have suspected a link between the mutated ATM gene and breast cancer. This study has provided the medical community with increased proof of its role in breast cancer.