Ordering Recommendation

Recommended initial test for suspected CMT1 or CMT1A. PMP22 gene deletion/duplication analysis is performed first. If negative or inconclusive, testing reflexes to sequencing of genes related to CMT and hereditary neuropathies.

New York DOH Approval Status

This test is not New York state approved. There are no New York state-approved laboratories available. Submit a Non-Permitted Laboratory Request Form (NPL) to the NYDOH prior to collection of specimen. If NPL is approved by NYDOH, and sample is received at ARUP, testing will be performed.

Specimen Required

Patient Preparation
Collect

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

Specimen Preparation

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

Storage/Transport Temperature

Refrigerated. Also accetable: Ambient.

Unacceptable Conditions
Remarks
Stability

Room temperature: 1 week; Refrigerated: 1 month; Frozen: Unacceptable

Methodology

Multiplex Ligation-Dependent Probe Amplification (MLPA)/Massively Parallel Sequencing

Performed

Varies

Reported

7-14 days
If reflexed, add 10-15 days.

Reference Interval

By Report

Interpretive Data

Refer to report.

Compliance Category

Laboratory Developed Test (LDT)

Note

Deletion/duplication analysis is performed on all samples. If no large deletions or duplications are detected and/or results do not explain the clinical scenario, then sequencing of the Charcot-Marie-Tooth and related hereditary neuropathy genes will be added. Additional charges apply. If reflexed, an additional 3-6 weeks is required to complete testing.

GENE TESTED BY MLPA: PMP22
GENES TESTED BY SEQUENCING: AARS; AIFM1; ATL1; ATP7A; BAG3; BICD2; BSCL2; CCT5; DCTN1; DHTKD1; DNAJB2; DNM2; DNMT1*; DYNC1H1; EGR2; ELP1; FBLN5; FGD4; FIG4; GAN; GARS; GDAP1; GJB1; GNB4; HARS; HEXA; HINT1; HOXD10; HSPB1; HSPB3; HSPB8; IGHMBP2; INF2; KARS; KIF1A; KIF1B; KIF5A; LAS1L; LITAF; LMNA; LRSAM1; MARS; MED25; MFN2; MORC2; MPZ; MTMR2; NDRG1; NEFL; NGF; NTRK1; PDK3; PLEKHG5; PMP22; PRNP; PRPS1; PRX; RAB7A; REEP1; RETREG1; SBF1; SBF2; SCN9A; SETX*; SH3TC2; SLC12A6; SLC5A7; SPTLC1*; SPTLC2; TDP1; TFG; TRIM2; TRPV4; TTR; WNK1; YARS
*

* One or more exons are not covered by sequencing for the indicated gene; see Additional Technical Information.

Hotline History

N/A

CPT Codes

81324; if reflexed, add 81448

Components

Component Test Code* Component Chart Name LOINC
2012156 Charcot-Marie-Tooth Reflex Specimen 31208-2
2012158 Charcot-Marie-Tooth (CMT) Reflex Interp 35464-7
* 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

  • Charcot-Marie-Tooth
  • CMT
  • CMT1
  • CMT1A
  • CMT2
  • CMT4
  • CMTX
  • Hereditary Motor Neuropathy (dHMN)
  • Hereditary Neuropathy
  • Hereditary Neuropathy with liability to Pressure Palsies (HNPP)
  • Hereditary Sensory and Autonomic Neuropathy (HSAN)
  • Hereditary Sensory Neuropathy (HSN)
Charcot-Marie-Tooth (CMT) and Related Hereditary Neuropathies, PMP22 Deletion/Duplication with Reflex to Sequencing Panel