Myotonic Dystrophy 2 (DM2) (CNBP repeat analysis)
Use
This test analyzes the CCTG tetranucleotide repeat expansion in intron 1 of the CNBP (ZNF9) gene, which causes the autosomal dominant disorder Myotonic Dystrophy type 2 (DM2). It is appropriate for patients with suspected DM2, especially when DM1 testing is negative or there is a family history consistent with DM2.
Special Instructions
Requires a completed GeneDx Neurology Test Requisition accompany the sample. Special shipping considerations: use ambient temperature shipping with FedEx Priority Overnight, mark for Saturday delivery if shipping on Friday.
Limitations
Blood specimens older than 7 days may still be tested if DNA yield and quality are sufficient. Samples will be rejected if frozen, hemolyzed, or clotted. Frozen specimens are unacceptable for testing.
Methodology
PCR-based (PCR)
Biomarkers
Result Turnaround Time
21 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
5 mL
Minimum Volume
2 mL (Infants: 1–2 mL)
Container
EDTA whole blood tube
Storage Instructions
Store and transport at ambient temperature; refrigerate if not sent the same day
Causes for Rejection
Frozen, hemolyzed, or clotted specimens
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |
| Refrigerated | 7 days |