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3001907
Myotonic Dystrophy Type 1 (DMPK) CTG Expansion
DM1 PCR
Ordering Recommendation
Use to diagnose myotonic dystrophy type 1 (DM1) in symptomatic individuals. May be used to screen for DM1 for adults with a family history. Specific allele sizing estimates cannot be determined for expanded alleles with greater than 150 CTG repeats.
New York DOH Approval Status
Testing is not New York state approved. Specimens from New York clients will be sent out to a New York state-approved laboratory.
Specimen Required
Patient Preparation
Collect
Lavender (K2EDTA), pink (K2EDTA), or yellow (ACD solution A or B)
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL)
Storage/Transport Temperature
Refrigerated. Also acceptable: Ambient.
Unacceptable Conditions
Remarks
Stability
Ambient: 1 week; Refrigerated: 1 month; Frozen: Unacceptable
Methodology
Polymerase Chain Reaction (PCR)/Capillary Electrophoresis
Performed
Varies
Reported
7-10 days
Reference Interval
By report
Interpretive Data
Refer to report
| Phenotype |
Number of CTG Repeats |
|---|---|
| Normal allele | Less than or equal to 34 |
| Premutation | 35-49 |
| Mild | 50-approx. 150 |
| Classic | Approx.100-approx. 1000 |
| Congenital | >1000 |
Compliance Category
Laboratory Developed Test (LDT)
Note
Hotline History
Hotline History
Date of Change
Test Name Change
Methodology
Performance/Reported Schedule
Specimen Requirements
Reference Interval
Interpretive Data
Note
CPT Code
Component Change
Other Interface Change
New Test
Inactive
N/A
CPT Codes
81234
Components
| Component Test Code* | Component Chart Name | LOINC |
|---|---|---|
| 3001908 | Myotonic Dystrophy (DM1) - Specimen | 31208-2 |
| 3001909 | Myotonic Dystrophy (DM1) - Allele 1 | 35751-7 |
| 3001910 | Myotonic Dystrophy (DM1) - Allele 2 | 35750-9 |
| 3001911 | Myotonic Dystrophy (DM1) Interpretation | 50398-7 |
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
- DM1
- DMPK
- Myotonic dystrophy
- Steinert disease
Myotonic Dystrophy Type 1 (DMPK) CTG Expansion
