Muscular dystrophies are inherited, progressive muscle disorders resulting from defects in one or more genes needed for normal muscle structure and function; dystrophic changes (eg, muscle fiber necrosis and regeneration) are seen on biopsy specimens.
Emery-Dreifuss dystrophy can be inherited as an autosomal dominant Autosomal Dominant Genetic disorders determined by a single gene (Mendelian disorders) are easiest to analyze and the most well understood. If expression of a trait requires only one copy of a gene (one allele)... read more , autosomal recessive Autosomal Recessive Genetic disorders determined by a single gene (Mendelian disorders) are easiest to analyze and the most well understood. If expression of a trait requires only one copy of a gene (one allele)... read more (the rarest), or X-linked recessive X-Linked Recessive Genetic disorders determined by a single gene (Mendelian disorders) are easiest to analyze and the most well understood. If expression of a trait requires only one copy of a gene (one allele)... read more disorder. The overall incidence is unknown. Females can be carriers, but only males are affected clinically by X-linked inheritance.
Genes associated with Emery-Dreifuss dystrophy encode for the following nuclear membrane proteins:
Lamin A/C (autosomal)
Nesprin-1 and nesprin-2
SUN1 and SUN2
Titin (a sarcomere protein)
Symptoms and Signs of Emery-Dreifuss Dystrophy
Muscle weakness and wasting can begin any time before age 20 and commonly affect the biceps and triceps and, less often, distal leg muscles. Early contractures are characteristic.
The heart is frequently involved, with atrial paralysis, conduction abnormalities (atrioventricular block Atrioventricular Block Atrioventricular (AV) block is partial or complete interruption of impulse transmission from the atria to the ventricles. The most common cause is idiopathic fibrosis and sclerosis of the conduction... read more ), cardiomyopathy Overview of Cardiomyopathies A cardiomyopathy is a primary disorder of the heart muscle. It is distinct from structural cardiac disorders such as coronary artery disease, valvular disorders, and congenital heart disorders... read more , and a high likelihood of sudden death.
Diagnosis of Emery-Dreifuss Dystrophy
DNA mutation analysis
Sometimes muscle biopsy
Diagnosis of Emery-Dreifuss dystrophy is indicated by clinical findings, age at onset, and family history.
The diagnosis is supported by mildly increased serum creatine kinase levels and myopathic features on electromyography. Mutation analysis of DNA from peripheral blood leukocytes is the primary confirmatory test.
If genetic testing does not confirm the diagnosis, then muscle biopsy can be done.
Treatment of Emery-Dreifuss Dystrophy
Therapy to prevent contractures
Treatment of Emery-Dreifuss dystrophy involves therapy to prevent contractures.
Cardiac pacemakers Cardiac Pacemakers The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. Treatment is directed at causes. If necessary, direct antiarrhythmic therapy, including antiarrhythmic... read more are sometimes lifesaving in patients with abnormal cardiac conduction.
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
Muscular Dystrophy Association: Information on research, treatment, technology, and support for patients living with Emery-Dreifuss muscular dystrophy
National Organization for Rare Disorders: Comprehensive information regarding Emery-Dreifuss muscular dystrophy, including standard and investigational therapies and links to related topics