GJB2 sequencing, full gene sequencing

Alphabetical Test listing

GJB2 sequencing, full gene sequencing-994

This test is orderable only by a genetic counselor.

Test name:

GJB2 sequencing, full gene sequencing

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

Connexin 26
Hearing Loss (GJB2)

Tests included:

Detects mutations in the coding region and noncoding first exon of the (GJB2) gene, plus at least two and typically 20 flanking intronic nucleotides upstream and downstream of each coding exon, covering the conserved donor and acceptor splice sites.

Useful for:

Confirms a diagnosis of GJB2-related nonsyndromic sensioneural hearing loss; detects carriers.

Limitations:

This method does not reliably detect mosaic variants; large deletions; large duplications, inversions, or other rearrangements; deep intronic variants or variants outside of the regions targeted by this analysis. It may be affected by allele-dropout, it may not allow determination of the exact numbers of T/A or microsatellite repeats, and it does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies.

This test is orderable only by a genetic counselor.

Specimen type:

EDTA whole blood

Collection container:

Lavender (EDTA), 4mL x2

Volume:

7 mL

Minimum volume:

3 mL

Collection instructions:

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

Transport container:

Lavender (EDTA), 4mL x2

Alternate specimen type:

Amniotic fluid
CVS

Alternate collection container:

Sterile screw cap vial/tube - 15mL (LabCorp)

Two confluent T-25 flasks for fetal testing

Alternate specimen volume:

Amniotic fluid - 10mL (5 mL minimum)
CVS - 20 mg (10 mg minimum)

Alternate transport container:

Sterile plastic conical tube

Two confluent T-25 flasks for fetal testing

Transport and stability:

Ambient (preferred)

Refrigerated (OK)

Frozen - NO

Reason for rejection:

Frozen specimen
Hemolysis
Quantity not sufficient for analysis (QNS)
Improper container

Performing lab:

LabCorp (511405): R-NX

Days set up:

Varies

TAT:

21 days

Method:

DAN sequencing

Reference ranges:

An interpretive report will be provided

CPT codes:

81252

Subject to medical necessity (Y/N):

Yes

Other billing information:

Medical necessity

Hospital clients submitting a request for this assay on an outpatient with Medicare should complete and submit a Molecular Medical billing request form along with the sample.

Complete and submit the form to notify us of the need for Allina Health Laboratory to bill insurance for Molecular testing performed
All information requested is required in order for your request to be completed

Molecular Medicare billing request

Date created:

04/26/2022

Revised date:

01/31/2024

Review date:

04/26/2022