title: Autosomal dominant muscle cramp syndrome in a Japanese family.
abstract: OBJECTIVE
  To identify the clinical, electrophysiological, histological, and genetic characteristics of a Japanese family with a muscle cramp syndrome.
  
  
  METHODS
  Fourteen patients (eight men, six women) were studied in four generations of a single family. Electrophysiological examinations were performed in four cases and muscle and nerve biopsies were performed on the propositus.
  
  
  RESULTS
  The mode of inheritance seemed to be autosomal dominant. The cramps occurred during both exertion and at rest, and during sleep. Electromyographic examination indicated a neurogenic aetiology. There was a decreased number of large myelinated fibres in the sural nerve, and fibre type grouping in the quadriceps femoris muscle biopsy.
  
  
  CONCLUSIONS
  The autosomal dominant muscle cramp syndrome in this family is probably caused by a polyneuropathy.
authors.affiliation: Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo 060-8543, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Chiba
authors.forename: M
authors.initials: M
authors.lastname: Saitoh
authors.forename: Y
authors.initials: Y
authors.lastname: Hatanaka
authors.forename: M
authors.initials: M
authors.lastname: Kashiwagi
authors.forename: T
authors.initials: T
authors.lastname: Imai
authors.forename: H
authors.initials: H
authors.lastname: Matsumoto
authors.forename: R
authors.initials: R
authors.lastname: Minami
mesh_terms: D000368:Aged; D004576:Electromyography; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009120:Muscle Cramp / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D010375:Pedigree; D013577:Syndrome