Ordering Recommendation

Recommended test for suspected HNPP, appropriate first-tier test for suspected CMT1 or CMT1A; does not detect sequence variants. Recommended test if there is a known familial PMP22 deletion or duplication previously identified in a family member. A copy of the family member’s test result documenting the known familial variant is required.

Mnemonic
CMT DD
Methodology

Multiplex Ligation-dependent Probe Amplification

Performed

Varies

Reported

Within 14 days

New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval

By Report

Interpretive Data

Refer to report.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

81324

Components
Component Test Code* Component Chart Name LOINC
2012161 Charcot-Marie-Tooth/HNPP DelDup Specimen 31208-2
2012162 Charcot-Marie-Tooth/HNPP DelDup Interp 35474-6
* 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
  • Charcot-Marie-Tooth
  • CMT
  • Hereditary Neuropathy
  • Hereditary Neuropathy with liability to Pressure Palsies (HNPP)
Charcot-Marie-Tooth Type 1A (CMT1A)/Hereditary Neuropathy with Liability to Pressure Palsies (HNPP), PMP22 Deletion/Duplication