APOE and early-onset autosomal dominant Alzheimer disease: Recently, Ryman et al. (2014) performed a meta-analysis of actual symptom onset in multiple studies of dominantly-inherited Alzheimer’s disease including the DIAN, and considered prediction of age at symptom onset using ages of onset for parents, family average, and group-wise averages by mutation type, as well as APOE ɛ4 genotype and sex.