Emery-Dreifuss Muscular Dystrophy, X-Linked
Gene: EMD
Protein: emerin
Clinical Characteristics
- Joint contractures beginning in early childhood, especially of elbows, ankles and neck
- Slowly progressive muscle weakness, beginning in upper arms and lower legs and progressing to shoulders and hips
- Cardiac disease with conduction defects and arrhythmias
- Female carriers are at risk for cardiac disease
Inheritance pattern: X-linked; carrier females may be affected with cardiac disease
What Can Be Learned From This Test
Testing is performed by sequencing the entire coding region of EMD. This will detect point mutations, small deletions and small insertions. For females, the assay will not detect a partial or whole gene deletion. For males, a partial or whole gene deletion may appear as failure to amplify a region of the gene.
This assay will detect mutations in EMD in greater than 99% of individuals with a clear pattern of X-linked inheritance and/or with no emerin detected by immunodetection methods.
A negative test result does not rule out a diagnosis of Emery-Dreifuss muscular dystrophy (EDMD). X-linked EDMD can be caused by mutations in either EMD or FHL1. Autosomal dominant and autosomal recessive forms of EDMD can be caused by mutations in LMNA.
A negative test does not rule out a genetic cause of muscular dystrophy. There are many other genes associated with different types of muscular dystrophy, some of which have features in common with EDMD.
Sample Requirements
Draw 2ml–4ml of blood in EDTA/purple-top tube (minimum of 1ml–2ml for infants).
Turnaround time: 10-14 business days
CPT Codes and Cost
Full Gene Sequencing
- Code: 81405
- Cost: $500
Known Variant Testing
- Code: 81479
- Cost: $225
Additional Information