title: Neuromuscular junction acetylcholinesterase deficiency responsive to albuterol.
abstract: Congenital myasthenic syndrome caused by endplate acetylcholinesterase deficiency constitutes a rare autosomal recessive disease. We describe a child with early-onset ptosis, complete ophthalmoplegia, facial and proximal muscle weakness, easy fatigability, a decremental electromyographic response, and a repetitive compound muscle action potential not improved by anti-acetylcholinesterase medication. Mutation analysis of the collagenic tail of endplate acetylcholinesterase (COLQ) that encodes the collagenic structural subunit of acetylcholinesterase revealed two canonic splice-site mutations: a previously identified IVS15 + 1G>A mutation and a novel IVS2 - 1G>A mutation. Treatment with albuterol resulted in progressive improvement of muscle strength, exercise tolerance, and ophthalmoplegia. Further studies are needed of the efficacy of albuterol in different types of congenital myasthenic syndrome and the physiologic basis of its beneficial effects.
authors: Division of Child Neurology, Developmental Paediatrics, and Neurohabilitation, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong Special Administrative Region. sophehs@hku.hk
authors: Sophelia H S
authors: SH
authors: Chan
authors: Virginia C N
authors: VC
authors: Wong
authors: Andrew G
authors: AG
authors: Engel
mesh_terms: D000110:Acetylcholinesterase / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics; D000420:Albuterol / Q000494:pharmacology / Q000627:therapeutic use*; D002648:Child; D006801:Humans; D008297:Male; D020294:Myasthenic Syndromes, Congenital / Q000175:diagnosis / Q000188:drug therapy* / Q000201:enzymology*; D009469:Neuromuscular Junction / Q000187:drug effects / Q000201:enzymology*; D016896:Treatment Outcome
chemical_list: D000110:Acetylcholinesterase; D000420:Albuterol