Although blood-based GFAP increases, like SNAP25 increases, are more pronounced in Alzheimer’s disease compared with other neurodegenerative disorders such as frontotemporal dementia and Lewy body dementia,94,95 GFAP has demonstrated similar prognostic value for predicting both Alzheimer’s disease dementia and dementia due to other causes.95-97 In the current study population, Alzheimer’s disease pathology was largely absent, which makes it an unlikely driver of the observed relationships. The gene discussed is GFAP; the disease is early-onset autosomal dominant Alzheimer disease.