Myotonic Dystrophy 1 (DMPK) Genetic Testing (Repeat Expansion)
Special Instructions
This assay is not currently available in New York state.
Expected Turnaround Time
2 - 4 weeks
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Specimen Requirements
Specimen
Whole blood
Volume
4 mL
Minimum Volume
1 mL
Container
Lavender-top (EDTA) tube
Collection
Draw blood into EDTA tube.
Storage Instructions
Ship ASAP, but stable up to 5 days post-collection at room temperature. Do not freeze.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 5 days |
Refrigerated | 5 days |
Frozen | Do not freeze |
Causes for Rejection
Frozen blood EDTA tube
Test Details
Use
Type 1 myotonic dystrophy results from a mutation in the DMPK gene known as a trinucleotide repeat expansion. This mutation increases in the size of the repeated CTG segment in the DMPK gene. People with type 1 myotonic dystrophy have from 50 to 5,000 CTG repeats in most cells. The number of repeats may be even greater in certain types of cells, such as muscle cells.
Limitations
Maximum reportable sizing: 150 repeats.
This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.
Methodology
Repeat-Primed PCR (QP-PCR)
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