[Present-day clinico-genetic framework of Duchenne's muscular dystrophy]

The authors emphasize the importance of adding a genetic criterion to the definition of Duchenne dystrophy. The clinical characteristics, however, on the basis of recent molecular genetic studies, are sufficiently precise to make the condition heterogeneous: two types of Duchenne dystrophy, with or without mental retardation in affected boys; muscular dystrophy in girls with mild symptomatic weakness in "manifesting carriers" up to severe myopathy in girls, found to be associated with reciprocal chromosomal translocation (X-autosome), always at the same site, Xp21. Diagnostic use of Xp21 probes is now as necessary as EMG, muscle biopsy and serum CK assay for the definition of Duchenne muscular dystrophy.