IMMUNOSTAINING OF DYSTROPHIN AND UTROPHIN IN SKELETAL-MUSCLE OF DYSTROPHINOPATHIES

Immunostaining of biopsied skeletal muscle of 4 Duchenne (DMD), 12 Bec ker muscular dystrophy (BMD) and 3 DMD carriers' was performed using m onoclonal antibodies against dystrophin and utrophin. In DMD, dystroph in-negative staining was observed except for revertant fibers which sh owed different stain patterns for each antibody. In 7 BMDs, there was faint/patchy stain in cases of deletion between exons 45-52, while in one case there was deletion between exons 12-17 and no stain was noted relevant to the deletion site. Moreover, in 2 cases of undetectable d eletion, antibodies which recognize a terminal portion of the C-termin al domain revealed the absent stain. In DMD, the utrophin-positive fib ers corresponded to dystrophin-negative fibers. In BMD, this relations hip did not necessarily occur in each fiber. In DMD carriers, a cluste r of dystrophin-negative fibers which was positive for utrophin were p rominent. In dystrophinopathy, the immunostaining of dystrophin and ut rophin is useful, in combination with dystrophin gene analysis to make a definite diagnosis.