[Various central nervous system involvements in dystrophinopathy: clinical and genetic considerations]

Duchenne and Becker muscular dystrophies, generically called dystrophinopathy, are caused by mutations of the dystrophin gene. It is not surprising that mutations of the dystrophin gene cause various neurological symptoms, since dystrophin protein is found in the brain tissue as well as in the muscle fiber cell membrane. However, few studies have reported on the frequency of central nervous complications other than mental retardation. Also, the relationship between the types of abnormal dystrophin gene and central nervous symptoms remains to be revealed. Medical records of 200 patients with dystrophinopathy from 167 extended families who had visited our institution during the past 15 years were reviewed to elucidate the frequency of central nervous complications. Fifty-four (27%) had mental retardation (an intelligence quotient less than 70), 15 (7.5%) had autism, 12 (6%) had epilepsy. 8 (4%) had febrile convulsion. 131 of these patients also underwent genetic testing. All patients with central nervous symptoms except one pair of siblings had some form of genetic deficiency or duplication distal to exon 44. Central nervous symptoms other than mental retardation are also common in patients with dystrophinopathy. These central nervous complications may be associated with mutations in the isoforms derived from exon 44 to 79.