EMERIN DEFICIENCY AT THE NUCLEAR-MEMBRANE IN PATIENTS WITH EMERY-DREIFUSS MUSCULAR-DYSTROPHY

Mutations in the STA gene at the Xq28 locus have been found in patient s with X-linked Emery-Dreifuss muscular dystrophy (EDMD). This gene en codes a hitherto unknown protein named 'emerin'. To elucidate the subc ellular localization of emerin, we raised two antisera against synthet ic peptide fragments predicted from emerin cDNA. Using both antisera, we found positive nuclear membrane staining in skeletal, cardiac and s mooth muscles in the normal controls and in patients with neuromuscula r diseases other than EDMD. In contrast, a deficiency in immunofluores cent staining of skeletal and cardiac muscle from EDMD patients was ob served. A 34 kD protein is immunoreactive with the antisera - the prot ein is equivalent to that predicted for emerin. Together, our findings suggest the specific deficiency of emerin in the nuclear membrane of muscle cells in patients with EDMD.