MAPT and early-onset autosomal dominant Alzheimer disease: H1/H2 haplotypes have been shown to affect expression and/or splicing of MAPT[6]–[10] and have been associated with risk of several sporadic neurodegenerative disorders, including Alzheimer’s disease [11], progressive supranuclear palsy [12], corticobasal degeneration [13] and Parkinson’s disease [14].