The disease is characterized by low levels of the neurotransmitter acetylcholine (ACh) in the brain and, therefore, a possible treatment of AD is associated with increasing the amount of ACh in the cholinergic synapses by inhibiting the two types of cholinesterase enzymes (acetylcholinesterase AChE and butyrylcholinesterase BChE). The gene discussed is ACHE; the disease is Alzheimer disease.