NPTX2 and early-onset autosomal dominant Alzheimer disease: Lower baseline cerebrospinal fluid (CSF) NPTX2 levels have been shown to be associated with an earlier onset of mild cognitive impairment (MCI), a pre-dementia syndrome, even after CSF Alzheimer's Disease (AD) biomarkers (amyloid beta (Aβ<sub>42/40</sub>), and phosphorylated tau (p-tau<sub>181</sub>)) were considered.