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.

Mnemonic

CMT REFLEX

Methodology

Multiplex Ligation-dependent Probe Amplification/Massively Parallel Sequencing

Performed

Varies

Reported

Within 2 weeks, if reflexed add 3-6 weeks

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), or yellow (ACD Solution A or B).

Specimen Preparation

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

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Serum or plasma; grossly hemolyzed or frozen specimens

Remarks
Stability

Ambient: 1 week; Refrigerated: 1 month; Frozen: Unacceptable

Reference Interval

By Report

Interpretive Data

Refer to report.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

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