In Hereditary Breast and Ovarian Cancer (HBOC) communication of genetic test results with relatives is essential to cascade testing. According to privacy laws those identified with the pathogenic variant have the sole responsibility to share information about test results and implications to relatives. Up to 50% of biological relatives are unaware of relevant genetic information, suggesting that benefits of genetic testing are not communicated effectively. Interventions designed to help mutation carriers communicate with relatives are critical for cascade genetic testing. Technology could play a significant role in facilitating communication and genetic education within HBOC families The investigators will develop a digital health platform for Swiss and Korean HBOC families. The digital platform will be based on the Family Gene Toolkit (FGT), a web-based intervention designed to enhance communication of genetic test results within HBOC families that has been tested for acceptability, usability, and participant satisfaction. The investigators will expand a Swiss research infrastructure to enable future collaborative projects between the two countries. Specific Aims 1. Develop a digital health platform to support the communication of cancer predisposition in HBOC families, based on linguistic and cultural adaptation methods of the FGT for the Swiss and Korean population 2. Develop the K-CASCADE research infrastructure in Korea by expanding the research infrastructure developed by the CASCADE Consortium in Switzerland 3. Evaluate the efficacy of the digital platform on psychological distress and communication of genetic test results, and knowledge of cancer genetics, coping, and decision making 4. Explore the reach, effectiveness, adoption, implementation, and maintenance of the digital platform The digital platform will be based on the FGT with linguistic adaptation for web and mobile access. Aim 1 will be achieved with focus groups with 20-24 HBOC mutation carriers and relatives and 6-10 providers involved in genetic services. For Aim 2, a Korean database of HBOC families (K-CASCADE) will be based on the Swiss CASCADE database. For Aim 3, feasibility and efficacy of the digital solution against the comparison intervention will be assessed in a randomized trial with a sample of 104 HBOC mutation carriers (52 in each arm). Aim 4 will be achieved with survey and interview data collected from HBOC families and healthcare providers during all phases of the study.