Unusual expression of emerin in a patient with X-linked Emery-Dreifuss muscular dystrophy

We report on a patient with the typical clinical findings of Emery-Dreifuss muscular dystrophy due to a mutation in the emerin gene that should have p roduced a higher molecular weight protein. Immunohistochemical analysis sho wed emerin localized only in the cytoplasm of muscle fibres and lymphoblast oid cells. The emerin molecule contained the nucleoplasmic domain and the t ransmembrane domain responsible for nuclear membrane targeting, so its inco rrect localization and lack of function could be due to abnormal folding re sulting in rapid degradation or inability to bind other nuclear proteins. ( C) 2000 Elsevier Science B.V. All rights reserved.