Muscle membrane-skeleton protein changes and histopathological characterization of muscle-eye-brain disease

Muscle-eye-brain disease belongs to congenital muscular dystrophies with central nervous system abnormalities. The etiology of MEB is still unknown. but abnormal immunoreactivity for laminin-2 has been reported. To evaluate disease progression in muscle tissue, 32 biopsy specimens from 17 muscle-eye-brain patients were analysed. The samples of four patients were studied by immunohistochemical techniques and by quantitative Western blotting. The samples showed a great variation in the muscle pathology. Regenerative fibers and mild fiber size variation were present in over 60%. At infancy, necrotic and regenerative fibers were common, while fat infiltration was the most prominent finding in the age group over live years. In quantitative studies, the amount of laminin cu? chain was clearly reduced to 10-20% of normal. In contrast, laminin beta 2 chain was overexpresed in the Western blotting studies. These findings may reflect a yet unidentified primary disturbance in the basement membrane composition and function. (C) 2000 Elsevier Science B.V. All rights reserved.