Emery-Dreifuss Muscular Dystrophy Type 2

Abstract

Emery-Dreifuss muscular dystrophy (EDMD) is a progressive myopathy characterized by a clinical triad including slowly progressive muscle weakness and atrophy (initially with a humero-peroneal distribution but later becoming more diffuse); joint contractures of the Achilles, elbow, and neck tendons, beginning during early childhood and leading to limited joint movement; and cardiac anomalies (conduction defects, rhythm disturbances, and dilated cardiomyopathy), which usually manifest after age 20 and may lead to sudden death and ischemic accidents due to embolism.

Autosomal dominant EDMD is caused by mutations in the LMNA gene (Table 5.1), which encodes lamin A/C localized to the nuclear envelope. The gene undergoes an alternative splicing encoding at least four different RNAs and related proteins. There is a striking frequency of de novo mutation, and therefore many cases might appear as sporadic.