CSF samples from patients with sporadic Creutzfeldt–Jakob disease (CJD), Alzheimer's disease (AD) and non-neurodegenerative controls (n = 18, respectively) were included in the study, and levels of myelin basic protein (MBP), neural/glial antigen 2 (NG2) and cyclic nucleotide 3′-phosphodiesterase (CNPase) were quantified. Here, CNP is linked to early-onset autosomal dominant Alzheimer disease.