NRGN and Alzheimer disease: Higher levels of SNAP-25 and Ng in patients with prodromal AD and AD dementia, and lower CSF levels of NPTX2 in AD patients compared to controls have been described before.11 - 17,37,38 In addition, we replicated previous findings by showing higher levels of synucleins and 14-3-3 proteins in AD compared to cognitively unimpaired subjects.19,39