In their study, the investigators analyzed amyloid-1-42 in cerebrospinal fluid (CSF) specimens from 101 cognitively unimpaired individuals enrolled in the Presymptomatic Evaluation of Novel or Experimental Treatments for Alzheimer Disease (PREVENT-AD) cohort. They estimated each participant’s closeness to their parent’s symptom onset by subtracting their relative’s onset age from their current age. Using CSF and Pittsburgh compound B carbon 11–labeled positron emission tomography (PIB-PET) amyloid- biomarkers, they performed analyses again in the Adult Children Study (ACS) and Wisconsin Registry for Alzheimer Prevention (WRAP) cohorts. {read more here}