Ordering Recommendation

Recommended test for suspected hereditary neuropathy with liability to pressure palsies (HNPP) and appropriate first-tier test for suspected Charcot-Marie-Tooth type 1 (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.

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

Lavender (EDTA), pink (K2EDTA),  or yellow (ACD solution A or B).
New York State Clients: Lavender (EDTA)

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)
New York State Clients: 5 mL (Min: 2 mL)

Storage/Transport Temperature

Preferred transport temp: Refrigerated. Also acceptable: Room temperature.
New York State Clients: Refrigerated

Unacceptable Conditions

Room temperature: 1 week ; Refrigerated: 1 month; Frozen: Unacceptable
New York State Clients: Ambient: 24 hours; Refrigerated: 1 week; Frozen: Unacceptable


Multiplex Ligation-Dependent Probe Amplification (MLPA)




7-14 days

Reference Interval

By Report

Interpretive Data

Refer to report.

Compliance Category

Laboratory Developed Test (LDT)


Hotline History


CPT Codes



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.


  • 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