Mondo Description Spheroid body myopathy is a rare form of myofibrillar myopathy characterized by predominantly proximal muscle weakness (that could be either non- or slowly progressive), associated with spheroid body inclusions (composed of myofilamentous material within individual muscle fibers) in skeletal muscle biopsy. Presentation is varied and may range from asymptomatic to severe muscle weakness that manifests with absent Achilles reflexes, gait abnormality and/or other motor incapacitations.

Uniprot Description Autosomal dominant form of myofibrillar myopathy (MFM), characterized by slowly progressing proximal muscle weakness and dysarthric nasal speech. There is no evidence of cardiomyopathy. Muscle biopsy shows spheroid bodies within the type I muscle fibers.