Test name: Dystrophinopathy (DMD) - Next Generation Sequencing
Disorders Included in This Panel:
- Dystrophinopathies GeneReviews™
- Becker muscular dystrophy (BMD)
- Duchenne muscular dystrophy (DMD)
- DMD-associated dilated cardiomyopathy
- Developmental delay
- Gross motor delay or loss of motor skills
- Low muscle tone
- Calf hypertrophy
- Abnormal gait
- Dilated cardiomyopathy
- Elevated serum CK
- Skeletal muscle biopsy showing decreased dystrophin quantity
The genes on this panel are included on another NGS panel offered by our laboratory:
For assistance determining which Next Gen panel is most useful for your patient, please call our laboratory at 402-559-5070 and ask to speak with a laboratory genetic counselor.
- Next generation sequencing (NGS), or “Next Gen” as it is frequently called, is a technology that analyzes multiple genes at once. It is a cost-effective method of testing many potentially causative genes simultaneously rather than ordering separate Sanger sequencing one gene at a time.
- Next Gen is most helpful in cases where a patient has findings suspicious of multiple potential genetic causes, generally the result of either clinical ambiguity due to marked phenotypic overlap between various syndromes or numerous genetic causes for a single disorder.
- Our systematic data analysis references the most current versions of primary genomic databases, which translates to better mutation classification (e.g., benign vs. pathogenic).
- Pathogenic changes are confirmed by traditional Sanger sequencing or by another appropriate testing method.
- Even after careful analysis, some variants cannot yet be classified as benign or pathogenic and, therefore, are variants of uncertain significance.
- Next Gen will identify sequence variation, but it will not identify large deletions or duplications. A complimentary test such as whole genome microarray analysis or gene-specific deletion/duplication analysis would be needed to identify genetic dosage abnormalities.
- Next Gen is NOT whole exome sequencing or whole genome sequencing. The test will only identify mutations in the genes included on the panel ordered.
Testing Strategy for Suspected Duchenne Muscular Dystrophy/Becker Muscular Dystrophy (DMD/BMD):
Deletions and duplications involving the DMD gene are a more common cause of Duchenne Muscular Dystrophy and Becker Muscular Dystrophy than sequence variations*. A tiered testing strategy is recommended.
*Reference Source: GeneReviews™
- Deletion/duplication analysis of the DMD gene using the High Density SNP Array or another method.
- Full High Density SNP Array analysis provides genome wide coverage. Upon request, results can be blinded to include only the DMD gene region.
- Next Generation Sequencing of the DMD gene.
Specimen requirements: Test kits are available – please contact the laboratory
- Blood: 3-5 ml in a EDTA tube (purple top)
CPT codes: 81479
Pricing: Contact the laboratory billing staff for current costs
Required forms: Postnatal Test Request Form
Turn-around time: Results are typically available in 6-10 weeks
1) Access the postnatal test request form on the Human Genetics Laboratory website.
2) Complete the 2-page form. Under TEST SELECTION, mark the box next to the Next Generation Sequencing DMD Sequencing. If ordering deletion/duplication analysis of DMD, also mark the box next to the Postnatal High Density SNP Microarray.
3) Under SPECIAL TEST INSTRUCTIONS, indicate the order in which you would like the tests performed. For example, “Please complete microarray first. If negative, reflex to DMD Sequencing.” Also indicate if you would like the results of the microarray blinded to only include the DMD gene region.
4) Provide any clinical information that may be important for interpretation.
5) Obtain insurance pre-authorization when necessary; forms available.
6) Following HGL shipping & handling requirements, send completed test request form and specimen at room temperature within 24 hours of collection.