Opening the psychological black box in genetic counseling. The psychological impact of DNA testing is predicted by the counselees' perception, the medical impact by the pathogenic or uninformative BRCA1/2-result

Background: It has been hypothesized that the Outcomes of DNA testing (O) are better predicted and/or mediated by the counselees' Perception P) than by the actually communicated genetic Information (I). In this study, we aimed at quantifying the effect that perception has in genetic counseling for hereditary breast/ovarian cancer. Methods: Two hundred and four women, who had previously been tested for BRCA1/2, participated in a retrospective questionnaire study; 93% had cancer. Communicated Information (I) consisted of cancer risks and BRCA1/2 test result category: unclassified variant (n=76), uninformative (n=76), pathogenic mutation (n=51). Four perception variables (P) were included: the counselees' recollections and interpretations of both the cancer risks and the likelihood that the cancer in their family is heritable. The Outcome variables (O) included life changes, counselees' medical decisions, BRCA-related self-concept, current psychological wellbeing, and quality-of-life. Bootstrap mediation analyses determined whether relationships were direct (I-O or P-O) or indirect through the mediation of perception (I-P-O). Results: The actually communicated pathogenic mutation and uninformative result directly predicted medical decisions (I-O), i. e. intended and performed surgery of breasts/ovaries. All other outcomes were only directly predicted by the counselees' perception (recollection and interpretation) of their cancer risks and heredity likelihood (P-O), or this perception mediated the outcome (I-P-O). However, this perception was significantly different from the actually communicated cancer risks (I-P). Unclassified variants were inaccurately perceived (mostly overestimated); this misperception predicted both psychological outcomes and radical medical decisions. Discussion: Genetic counselors need to explicitly address the counselee's interpretations and intended medical decisions. In case of misinterpretations, additional counseling might be offered. Communication of unclassified variants needs special attention given the pitfall of overestimation of risk.