Charcot-Marie-Tooth Type 1A (CMT1A)/Hereditary Neuropathy with Liability to Pressure Palsies (HNPP), PMP22 Deletion/Duplication
Also known as: CMT DD
Use
The test is recommended for suspected hereditary neuropathy with liability to pressure palsies (HNPP) and serves as an appropriate first-tier test for suspected Charcot-Marie-Tooth type 1 (CMT1) or CMT1A. It is also useful if there is a known familial PMP22 deletion or duplication previously identified in a family member. This test can confirm the diagnosis by detecting PMP22 gene deletions or duplications, which cause these conditions.
Special Instructions
For patients in New York State, the specimen will be sent to a New York state-approved laboratory. It is necessary to submit the Charcot-Marie-Tooth (CMT) and Hereditary Neuropathy Testing Patient History Form and obtain informed consent for genetic testing, especially for NY patients.
Limitations
The test does not detect sequence variants and may not identify single exon deletions/duplications depending on the breakpoints of the rearrangement. Single base pair substitutions, small deletions/duplications, regulatory region mutations, and deep intronic mutations are not detected. Large deletion/duplication breakpoints are not determined, and diagnostic errors can occur due to rare sequence variations.
Methodology
Other
Biomarkers
LOINC Codes
- 31208-2
- 35474-6
Result Turnaround Time
7-14 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
1 mL
Container
Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B)
Storage Instructions
Preferred transport temperature is refrigerated, but room temperature is also acceptable. For New York State clients, refrigerated transport is required.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 week |
| Refrigerated | 1 month |
| Frozen | Unacceptable |
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