From the accompanying JAMA Neurology editorial “What is clear is that, with the advance of molecular diagnostic tools in neurology, clinicians and investigators will increasingly be faced with the challenge of presenting patients with information of uncertain prognostic significance. The investigators of the A4 study are to be commended for developing a thoughtful process of disclosure for predictive biomarker findings, and Mozersky et al have performed valuable work in subjecting this disclosure process to further critical scrutiny.”