GLUCOCORTICOID-SENSITIVE HEREDITARY INCLUSION-BODY MYOSITIS

We report a hereditary muscle disorder with features of inclusion body myositis (IBM) in two adult sisters with slowly progressive asymmetri cal muscle weakness. The findings of light microscopic and ultrastruct ural investigations of muscle biopsy specimens were consistent with a diagnosis of IBM. Both patients improved and stabilized on immunosuppr essive treatment with corticosteroids and azathioprine. This different iates our patients from other sporadic and familial cases of IBM. Clin ical and histological features are described and compared with those o f other previously reported families with IBM.