Autosomal dominant muscle cramp syndrome in a Japanese family
- aDepartment of Neurology, School of Medicine, Sapporo Medical University, Sapporo 060–8543, Japan, bDepartment of Pediatric Neurology, National Sanatorium Yakumo Hospital, Yakumo 049–3116, Japan
- Dr Susumu Chiba, Department of Neurology, School of Medicine, Sapporo Medical University, Minami 1-Jo Nishi 16-Chome, Chuo-ku, Sapporo 060–8543, Japan. Telephone 0081 11 611 2111, ext 3821; fax 0081 11 622 7668.
- Received 29 May 1998
- Revised 19 November 1998
- Accepted 2 December 1998
Abstract
OBJECTIVES 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.
