Myotonia congenita (Thomsen's disease). Early diagnosis in infancy.

A family with myotonia congenita. (Thomsen's disease) is reported in which the father and his two offspring are affected. The course was characterized by the early onset of clinical manifestations in both the father and his two children. In one child, a clinical and electrical diagnosis of the disease was made as early as two weeks of age. Early manifestations were breathing difficulty and eye closure myotonia. The importance of early recognition of the disorder is emphasized.