A slowly progressive autosomal dominant neuromuscular disease--termed spheroid body myopathy--is described in four successive generations and documented by muscle biopsies in five patients of two generations. With an onset in adolescence, the disease proceeds to some motor incapacitation, but life span is apparently not shortened. The salient morphologic feature is the presence of spheroid bodies, chiefly occurring in type 1 myofibers. Ultrastructurally, these spheroid bodies are composed of tiny filaments but are devoid of organelles; in some cases they resemble cytoplasmic bodies. "Smearing in the 1-band" is a frequent and early finding. At a later age, signs of denervation are also present, both clinically and in muscle biopsies. The clinical and morphologic features justify the designation of this neuromuscular condition as a distinct entity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.