When quantified with the same method as in this study, individuals with Alzheimer’s disease had significantly higher CSF neurogranin levels than the other groups (median and interquartile range), 463 (275–669) pg/mL in Alzheimer’s disease, compared with 196 (120–297) pg/mL in healthy controls, 120 (120–304) pg/mL in Lewy body dementia, 156 (120–283) pg/mL in Parkinson’s disease, 188 (120–302) pg/mL) in progressive supranuclear palsy, and 191 (120–265) in multiple system atrophy. This evidence concerns the gene NRGN and Alzheimer disease.