MAPT and early-onset autosomal dominant Alzheimer disease: Alzheimer’s disease (AD) is characterised clinically by memory loss, cognitive impairment and behavioural problems [1], and neuropathologically by neuronal and synaptic loss and by various deposits containing the amyloid-beta protein (Aβ) and aggregated microtubule-associated protein tau in the form of neurofibrillary pathologies including neurofibrillary tangles (NFT), dystrophic neurites in neuritic plaques (NP) and neuropil threads (NT) [2].