Mutation Analysis of X-Linked Emery-Dreifuss Muscular Dystrophy Gene

Emery-Dreifuss muscular dystrophy (EDMD) is an X-linked muscular disease first described in the early 1960s in a family from Virginia (1 ) The disease is characterized by the triad of early contractures of the elbows, Achilles tendons, and postcervical muscles; slowly progressing muscle wasting and weakness, with humeroperoneal distribution in the early stages of the disease; and a cardiomyopathy usually presenting as heart block (2 –5 ). The cardiomyopathy manifests around the age of 20 yr as a cardiac conduction defect, and the associated heart block is a frequent cause of death. Provided that diagnosis is made sufficiently early, the insertion of a cardiac pacemaker can be lifesaving. In no case has mental retardation or an intellectual defect been described. Families in which EDMD is inherited as an autosomal dominant or recessive trait have been reported (6 ), but the majority of the EDMD cases are inherited as an X-linked recessive trait. Clinically, the three forms are very similar. For this reason, the term “Emery-Dreifuss syndrome” was proposed for the triad of symptoms (6 ) Molecular diagnosis is therefore very important for an early diagnosis, and to distinguish X-linked EDMD from the autosomal forms, as well as from different MDs presenting with contractures.