Differentiation of Becker muscular dystrophy from limb-girdle muscular dystrophy and Kugelberg-Welander disease using a cDNA probe.

A 31-year-old man previously investigated for a neuromuscular disorder was diagnosed as having either limb-girdle dystrophy, spinal muscular atrophy, or Becker muscular dystrophy. Extensive clinical and special neurological investigations failed to clarify this differential diagnosis. However, recent DNA studies have shown a deletion of the dystrophin gene, thereby providing an unequivocal diagnosis of Becker muscular dystrophy. The application of molecular genetic techniques in the diagnosis of inherited neuromuscular disorders is discussed.