The A-type lamins - Nuclear structural proteins as a focus for muscular dystrophy and cardiovascular diseases

Mutations in the lamin A (LMNA) gene are associated with the tissue-specifi c diseases Emery-Dreifuss muscular dystrophy (EDMD), limb girdle muscular d ystrophy (LGMD-1B), dilated cardiomyopathy with conduction system disease ( DCM-CD), and Dunnigan's familial partial lipodystrophy (FPLD). Lamins A and C, the products of the LMNA gene, are nuclear intermediate filament protei ns and are the major structural components of the lamina network that under lies and supports the nuclear envelope. Nuclear fragility and mislocalizati on of the nuclear envelope protein emerin are two defects induced by a lack of the A-type lamins. These observations reveal that organization and stru ctural integrity of the nucleus are critical factors in the origins of cert ain dystrophic and cardiovascular diseases. (Trends Cardiovasc Med 2001; 11 :280-285). (C) 2001, Elsevier Science Inc.