The BCHE gene codes for the BuChE (butyrylcholinesterase) enzyme. This enzyme binds to various substrates, including Cholinesterase Inhibitors (CIs), and plays a role in protecting the neurotransmitter AChE (acetylcholine) from inhibitition. BuChE activity is also leveraged by various pharmaceuticals, such as succinylcholine, to control duration of action.
Variations in the BCHE gene, most notably rs1799807, can alter the structure, substrate specificity, and/or activity of BuChE. These variations can result in atypical reactions to CIs and altered behavior/toxicity of pharmaceuticals which base dosage and timing assumptions on the behavior of the most common BuChE version(s).