Late onset and very mild course of Xp21 Becker type muscular dystrophy.

We report a case of late onset of Becker's muscular dystrophy (BMD), diagnosed at the age of 60, which showed a very mild clinical course. Remarkably, the immunohistochemical pattern did not show significant alterations, while Western blotting disclosed low molecular weight dystrophin. DNA analysis showed a deletion of the exons 45-53 of the Xp21 gene, which is fairly typical of Becker's muscular dystrophy but not predictable of clinical course. The possibility of Xp21 muscular dystrophy must be considered in all myopathies of uncertain cause, also in elderly patients.