Inclusion body myositis refers to a group of conditions which share some clinical features of progressive muscle weakness and wasting and also have similar features on a muscle biopsy, where so-called inclusion bodies or rimmed vacuoles are seen. Sporadic inclusion body myositis (IBM) presents with slowly progressive distal and proximal muscle weakness, often with years between onset of symptoms and diagnosis. It is the most common inflammatory myopathy in men older than 50. It is distinguished from inherited IBM as there is also evidence of inflammation, not present in inherited IBM. Inherited IBM is typically a slowly progressive muscle disease that typically presents with bilateral foot drop between ages 20 and 40 years. Affected individuals have genetic faults in both copies of their GNE gene.
MDFSA Blog
Blog of the Muscular Dystrophy Foundation of South Africa