CNP and early-onset autosomal dominant Alzheimer disease: Frontotemporal dementia is also associated with myelin degeneration in the frontal white matter, and Alzheimer's disease results in an early and progressive reduction in white matter cholesterol and myelin proteins, such as myelin basic protein, proteolipid protein and 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase (CNP) (Roher et al., 2002), and a reduction in CNP expression (Vlkolinský et al., 2001) and impaired myelin lipid synthesis (Couttas et al., 2016) in the frontal grey matter.