Deficiency of butyrylcholinesterase

Individuals deficient in butyrylcholinesterase (BCHE) appear asymptomatic, apart from a heightened sensitivity to muscle relaxants such as suxamethonium (succinylcholine) and mivacurium, 2 BCHE carboxylester substrates. In individuals with usual BCHE levels, these drugs are rapidly hydrolyzed in plasma and their duration of action is short (less than 10 minutes). BCHE deficiency results in slower hydrolysis of these drugs and, consequently, a prolonged neuromuscular block, leading to apnea. Prolonged neuromuscular block occurs with BCHE deficiencies of marked severity (impairment over 70%). Although many acquired conditions may affect BCHE activity (e.g., liver or renal diseases, malnutrition, pregnancy, malignancy), BCHE deficiency is mainly due to mutations in the BCHE gene (summary by Delacour et al., 2014). [from OMIM]