Cholinesterases, such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), are enzymes responsible for acetylcholine cleavage, and their inhibition, with the consequent enhancement of cholinergic transmission, represents the therapeutic approach most widely exploited for the treatment of Alzheimer’s disease, albeit only palliative. Here, BCHE is linked to early-onset autosomal dominant Alzheimer disease.