Myotonic Dystrophy 2 (ZNF9/CNBP) Genetic Testing (Repeat Expansion)

Alphabetical Test listing

Myotonic Dystrophy 2 (ZNF9/CNBP) Genetic Testing (Repeat Expansion)-994

Test name:

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

DM2

Useful for:

Type 2 myotonic dystrophy results from a mutation in the CNBP gene known as a tetranucleotide repeat expansion. This mutation increases in size of the repeated CCTG segment in the CNBP gene. People with type 2 myotonic dystrophy have from 75 to more than 11,000 CCTG repeats.

Limitations:

Maximum reportable sizing: 373 repeats

This test was developed, and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Specimen type:

EDTA whole blood

Collection container:

Lavender (EDTA), 4mL

Volume:

4.0 mL

Minimum volume:

1.0 mL

Collection instructions:

Immediately following collection, mix sample thoroughly by gently inverting 8 - 10, times to prevent clotting

Transport and stability:

Ambient - 5 days (preferred)

Refrigerated - 5 days

Do not freeze

Ship as soon as possible

Reason for rejection:

Frozen specimen

Performing lab:

LabCorp (620087): R-LC

Days set up:

2 x week

TAT:

2- 4 weeks

Method:

Repeat-Primed PCR (QP-PCR)

Reference ranges:

See report for interpretation

Preauthorization:

This test may require preauthorization from the insurance provider. Check the payer guidelines and, if needed, obtain the pre-authorization prior to sample collection.

CPT codes:

81187

Date created:

11/02/2022

Revised date:

06/23/2023

Review date:

11/02/2022