title: [Beneficial effects of 3,4-diaminopyridine in a 26-year-old woman with DOK7 congenital myasthenic syndrome who was originally diagnosed with facioscapulohumeral dystrophy].
abstract: We report a 26-year-old woman who had respiratory dysfunction and muscle weakness at birth and was diagnosed with facioscapulohumeral dystrophy at the age of 5. The extent of muscle weakness fluctuated daily or weekly and deteriorated in menstrual periods. At the age of 12, she noted improvements in symptoms when taking procaterol hydrochloride and began to take it regularly. After that, her condition stabilized. At the age of 26, she visited our hospital presenting with ptosis, muscle weakness in the face, trunk, and proximal limbs, and easy fatigability. Serum CK was normal; anti-acetylcholine receptor and anti-muscle specific tyrosine kinase antibodies were negative. A repetitive stimulation test in the trapezius muscle showed a waning phenomenon. Gene analysis for congenital myasthenic syndrome (CMS) revealed a new mutation in the DOK7 gene; the diagnosis of CMS was confirmed. Her symptoms worsened with ambenonium chloride but improved with 3,4-diaminopyridine. Our findings suggest that daily or weekly fluctuation and worsening with a menses in muscle weakness is an important diagnostic feature of CMS.
authors.affiliation: Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Nishikawa
authors.forename: Madoka
authors.initials: M
authors.lastname: Mori-Yoshimura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Okamoto
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Oya
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Nakata
authors.forename: Kinji
authors.initials: K
authors.lastname: Ohno
authors.forename: Miho
authors.initials: M
authors.lastname: Murata
mesh_terms: D015761:4-Aminopyridine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000328:Adult; D000077770:Amifampridine; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology; D009124:Muscle Proteins / Q000235:genetics*; D020391:Muscular Dystrophy, Facioscapulohumeral; D009154:Mutation; D020294:Myasthenic Syndromes, Congenital / Q000175:diagnosis / Q000188:drug therapy* / Q000235:genetics*; D010507:Periodicity; D026902:Potassium Channel Blockers / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: C511692:DOK7 protein, human; D009124:Muscle Proteins; D026902:Potassium Channel Blockers; D015761:4-Aminopyridine; D000077770:Amifampridine