[Structural and ultrastructural changes in the skeletal muscles of patients in the early stages of Duchenne muscular dystrophy and "possible" carriers].

In order to continue the morpho-functional investigations on the muscle of subjects with Duchenne muscular dystrophy, we have studied, by means of light and electron microscope, bioptic fragments of the gastrocnemius muscle, taken from apparently healthy carriers, who had been diagnosed through laboratory tests. The first results obtained stress not only some initial alterations of the muscle fibres (variation in their caliber, with focal hyaline degeneration, necrosis, increase in the number of their nuclei etc.), but also modifications of the connectival structure of the muscle. In fact, both endomysium and perimysium appear noticeably packed, rich in collagen fibrils within a fundamental more electrondense than usual, and frequently showing a granulofilamentous aspect. Many polymorph fibroblasts stretch out thin digitations towards the capillary wall and the sarcolemmal membrane. These alterations are similar to those observed in the skeletal muscles of subjects with DMD in early age or in the preclinical stage of the disease.