Acetylcholinesterase (EC 3.1.1.7) (AChE) and butyrylcholinesterase (EC 3.1.1.8) (BChE) have gained attention due to their roles in Alzheimer disease (AD) and other Central Nervous System (CNS) conditions, such as delirium and traumatic brain injuries, associated with deficient levels of acetylcholine (ACh)6. Here, ACHE is linked to early-onset autosomal dominant Alzheimer disease.