Spanish family with myalgia and cramps syndrome

A Spanish family is reported with dystrophinopathy of myalgia and cramps syndrome type. There were five affected males and three females, and also six asymptomatic carriers. Muscle biopsy showed a dystrophic pattern, but immunohistochemistry carried out with three anti-dystrophin antibodies was normal. Dystrophin analysis by western blot revealed a dystrophin of reduced quantity and molecular weight. DNA analysis showed a deletion of the dystrophin gene involving exons 45-52. The natural history of this disorder and the large intrafamilial clinical variability are discussed.