Intracytoplasmic inclusions in the atrophic muscle fibers in Werdnig-Hoffmann disease.

ABSTRACT

In the biopsied muscle from a male infant having clinical and pathological characteristics of Werdnig-Hoffmann disease, unusual intracytoplasmic inclusions measuring from 1.5-7 micron in dimension were observed in approximately 3% of the atrophic fibers. Although the ultrastructural characteristics of the inclusion were almost identical to that of "cytoplasmic body" seen in various neuromuscular disorders, which showed somewhat different histochemical reactions. This unusual structure was assumed to have originated from degenerated myofibrils and possibly from mitochondria, while the significance of the body formation still remains to be solved.