Dystrophin-positive fibers in Duchenne dystrophy: origin and correlation to clinical course.
In 132 DMD muscle biopsies we investigated the presence of dystrophin-positive fibers and the relationship of dystrophin immunohistochemical pattern to the clinical severity of the disease. Reverted fibers were detected in 37% of patients; their prevalence increased significantly in each biopsy with age of patients. We suggest that reversion occurs in satellite cells, when muscle differentiation is completed. The longitudinal extent of dystrophin-positive domain spans a maximum length of 900 microns. No correlation was found between the presence of reverted fibers and the clinical severity of DMD, whereas a milder form of Duchenne dystrophy was observed in patients showing a faint reaction in all fibers. The occurrence of reverted fibers is independent of the type of gene mutation; however, a higher proportion of cases with reverted fibers was found among patients with gene duplications.
Fanin
M
M
Department of Neurology, University of Padova, Italy.
Danieli
G A
GA
Cadaldini
M
M
Miorin
M
M
Vitiello
L
L
Angelini
C
C
D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D018076:DNA, Complementary; D016189:Dystrophin / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D008957:Models, Genetic; D018485:Muscle Fibers, Skeletal / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D009136:Muscular Dystrophies / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009154:Mutation; D012720:Severity of Illness Index; D013997:Time Factors
D018076:DNA, Complementary; D016189:Dystrophin