Nuclear changes in a case of X-linked Emery-Dreifuss muscular dystrophy

Ultrastructural alterations in the nuclear architecture were found in skele tal muscle and skin cultured cells from a patient affected by X-linked Emer y-Dreifuss muscular dystrophy (EMD) carrying a null mutation. The molecular defect of X-linked EMD is the absence of emerin, a nuclear envelope-associ ated protein which is considered a component of the nuclear lamina. The nuc lear changes were present in skeletal muscle and skin cultured cells with a frequency of about 10% and 18%, respectively. The main structures of the n uclear periphery were involved: lamina and nuclear envelope-associated hete rochromatin were affected, whereas the cisterna and the pore complexes appe ared preserved, and the cytoplasm of the same cells appeared normal. Analog ous localized defects were detectable by immunolabeling with antilamin A/C and B2 antibodies, as well as by selective propidium iodide chromatin stain ing. The lesions we describe could be the result of anomalous nuclear lamin a organization in the absence of emerin. (C) 1999 John Wiley & Sons, Inc.