MONDAY, Jan. 9 (HealthDay News) -- Most parents who have genetic tests for breast cancer risk share the findings with their children, a new study finds.

Researchers interviewed 253 parents who underwent genetic testing for mutations in two common breast cancer-related genes (BRCA1 and BRCA2) that can be inherited. All the participants had children younger than age 25 at the time of the genetic test.

Twenty-nine percent of the parents were found to have a BRCA gene mutation associated with an increased risk of breast cancer, said Dr. Angela Bradbury, of the Fox Chase Cancer Center in Philadelphia, and colleagues.

Most of the parents in the study shared their test results (positive or negative) with at least one of their children. Of the 505 children, 334 (66 percent) were informed about the findings of their parents' tests.

Parents were more likely to share their test results with older children, but results were shared with about half of children ages 10 to 13, and some children who were even younger.

The researchers also found that parents were more likely to tell their children about negative test results -- meaning no breast cancer-related mutation was found -- particularly if the child was a girl.

Most children were not distressed when told about their parents' test results, but they were more likely to be upset when a mutation was detected and when they were younger than age 10, according to the report published online Jan. 9 in the journal Cancer.

"We know that adolescence is a time when children establish many important health behaviors they continue in adulthood. An understanding about children's reactions to these communications may assist parents in their decisions about whether, or when, to share their genetic test results," Bradbury said in a journal news release.

"This could also help parents begin conversations with their children that can encourage them to adopt healthy behaviors but not cause them distress," she added.

More information

The American Association for Clinical Chemistry has more about BRCA1 and BRCA2 tests.