Duchenne and Becker Muscular Dystrophy (DMD) MLPA
|Disorder||Duchenne Muscular Dystrophy
Becker Muscular Dystrophy
|Clinical info||Both Duchenne muscular dystrophy and the milder Becker muscular dystrophy are due to mutations in the dystrophin gene located on the X chromosome. The characteristic features of these disorders include pseudohypertrophy of the calf muscle, myofiber degeneration, myopathic EMG changes, and dramatic elevations of serum creatine kinase. Approximately two-thirds of mutations in the dystrophin gene are due to deletions and duplications. The majority of the remaining dystrophin defects result from point mutations within the gene.|
|Indications||Molecular testing is useful to confirm the diagnosis and to identify the disease causing deletion or duplication within a family to allow for carrier testing and prenatal diagnosis.|
|Detection||Testing for Duchenne and Becker muscular dystrophy involves multiple ligation-dependent probe amplification (MLPA) analysis that can detect up to 98% of all deletions and duplications in muscular dystrophy in patients and females that carry the mutation. Approximately 75% of patients with DMD and 95% of individuals with BMD will have a deletion or duplication.|
|Specimen Requirements||5 to 10 ml of peripheral blood collected in an EDTA (lavender top) Vacutainer tube is preferred. The minimal blood needed for reliable DNA isolation is 3 ml|
|Transport||The specimen should be kept at room temperature and delivered via overnight shipping. FedEx is preferred. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.|
|Turnaround time||2 weeks|
|Prenatal testing||Prenatal diagnosis is available if a familial deletion or duplication has been confirmed. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.|
Prenatal diagnosis is $1000. Please contact the laboratory for more information.
Molecular Diagnostic Lab
The Molecular Diagnostic Lab offers DNA analysis for many genetic disorders via gene sequencing, targeted mutation analysis, MLPA deletion/duplication testing, trinucleotide repeat analysis and next generation sequencing panels.