[Myotonia congenita with familial spastic paraparesis].

An association of myotonia congenita and hereditary spastic paraplegia has not been reported up to now. We present three cases in one family, who suffer from this combination of syndromes. There are no hints for a pathophysiological connection between these diseases of different systems. A combination of autosomal dominant myotonia congenita and autosomal recessive spastic paraplegia is supposed. Under this hypothesis the risk for an association of the syndromes in the last generation of the reported family with two affected patients is 1/36. A coincidence of these two hereditary diseases seems to be possible.