The Value of Knowing When: An Ethical Analysis of Onset Prediction in Genetic Neurodegenerative Diseases.

Biomarker-based technologies for predicting age of onset are currently being developed for carriers and individuals at 50% risk of autosomal dominant neurodegenerative diseases such as Huntington's disease, frontotemporal dementia and spinocerebellar ataxias. Qualitative interview studies indicate that carriers and individuals at 50% risk expect that onset predictions would be valuable for life planning but would also impact mental health. Ethically responsible implementation of biomarker-based onset prediction in research and clinical settings requires maximizing the utility and minimizing negative psychosocial effects. We present a framework specifying features that influence the value and impact of onset predictions, grouped into four domains: features of the disease, the onset-predictive test, the individual, and the context. The framework is intended to support ethicists, researchers, developers, and healthcare professionals in anticipating and addressing the ethical implications of current and emerging onset prediction technologies for individuals at risk of genetic neurodegenerative disease.