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

Muscle-eye-brain disease belongs to congenital muscular dystrophies with ce ntral nervous system abnormalities. The etiology of MEB is still unknown. b ut abnormal immunoreactivity for laminin-2 has been reported. To evaluate d isease 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 s amples showed a great variation in the muscle pathology. Regenerative fiber s and mild fiber size variation were present in over 60%. At infancy, necro tic and regenerative fibers were common, while fat infiltration was the mos t prominent finding in the age group over live years. In quantitative studi es, 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 blottin g studies. These findings may reflect a yet unidentified primary disturbanc e in the basement membrane composition and function. (C) 2000 Elsevier Scie nce B.V. All rights reserved.