Several studies have also looked at the timing of disclosure to children after parents receive their test results. Although the majority of children were told within a week to several months after results disclosure,[122,127,128] some parents chose to delay disclosure. Reasons for delaying disclosure included waiting for the child to get older, allowing time for the parent to adjust to the information, and waiting until results could be shared in person (in the case of adult children living away from home).
One study looked at the reaction of children to results disclosure or the effect on the parent-child relationship of communicating the results. With regard to offspring's understanding of the information, almost half of parents from one study reported that their child did not appear to understand the significance of a positive test result, although older children were reported to have a better understanding. This same study also showed that 48% of parents reported at least one negative reaction in their child, ranging from anxiety or concern (22%) to crying and fear (26%). It should be noted, however, that in this study children's level of understanding and reactions to the test result were measured qualitatively and based only on the parents' perception. Also, given the retrospective design of the study, there was a potential for recall bias. There were no significant differences in emotional reaction depending on age or gender of the child. Lastly, 65% of parents reported no change in their relationship with their child, while 5 parents (22%) reported a strengthening of their relationship.
Another study of 187 mothers undergoing BRCA1/BRCA2 testing evaluated their need for resources to prepare for a facilitated conversation about sharing their BRCA1/BRCA2 testing results with their children. Seventy-eight percent of mothers were interested in three or more resources, including literature (93%), family counseling (86%), talking to prior participants (79%), and support groups (54%).
Testing for BRCA1/BRCA2 has been almost universally limited to adults older than 18 years. The risks of testing children for adult-onset disorders (such as breast and ovarian cancer), as inferred from developmental data on children's medical understanding and ability to provide informed consent, have been outlined in several reports.[145,146,147,148] Surveys of parental interest in testing children for adult-onset hereditary cancers suggest that parents are more eager to test their children than to be tested themselves for a breast cancer gene, suggesting potential conflicts for providers.[149,150] In a general population survey in the United States, 71% of parents said that it was moderately, very, or extremely likely that if they carried a breast-cancer predisposing mutation, they would test a 13-year-old daughter now to determine her breast cancer gene status. To date, no data exist on the testing of children for BRCA1/BRCA2, though some researchers believe it is necessary to test the validity of assumptions underlying the general prohibition of testing of children for breast/ovarian cancer and other adult-onset disease genes.[151,152,153] In one study, 20 children (aged 11-17 years) of a selected group of mothers undergoing genetic testing (80% of whom previously had breast cancer and all of whom had discussed BRCA1/BRCA2 testing with their children) completed self-report questionnaires on their health beliefs and attitudes toward cancer, feelings related to cancer, and behavioral problems. Ninety percent of children thought they would want cancer risk information as adults; half worried about themselves or a family member developing cancer. There was no evidence of emotional distress or behavioral problems. Another study by this group  found that 1 month after disclosure of BRCA1/BRCA2 genetic test results, 53% of 42 enrolled mothers of children aged 8 to 17 years had discussed their result with one or more of their children. Age of the child rather than mutation status of the mother influenced whether they were told, as did family health communication style.