Ordering Recommendation

Diagnostic testing or carrier screening for GJB2-related nonsyndromic hearing loss (NHSL). May be used as first-tier genetic test for individuals with NSHL.

Mnemonic

CX26SEQ

Methodology

Polymerase Chain Reaction/Sequencing

Performed

Varies

Reported

14-21 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval

By report

Interpretive Data

Background Information: Connexin 26 (GJB2) , Sequencing
Characteristics:
Nonsyndromic hearing loss; recessive mutations typically cause congenital deafness while dominant mutations have variable expressivity.
Incidence:
Approximately 1:6500.
Inheritance:
Autosomal recessive or dominant depending on specific GJB2 mutation.
Cause:
 GJB2 gene mutations.
Clinical Sensitivity:
95 percent of GJB2 mutations.
Methodology:
Bidirectional sequencing of the entire coding region, exon/intron boundaries, and 5'-UTR of the GJB2 gene sequenced.
Analytical Sensitivity and Specificity
: Greater than 99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Large GJB2 gene deletions or deep intronic mutations will not be identified; hearing loss caused by other genetic or environmental causes will not be detected.

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

Hotline History

N/A

CPT Codes

81252

Components

Component Test Code* Component Chart Name LOINC
0051375 Connexin 26, Full Gene Sequencing 35300-3
2001348 CX26SEQ Specimen
* 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

  • Connexin 26 hearing loss
  • GJB2 hearing loss
  • Hearing Loss, Nonsyndromic
Connexin 26 (GJB2), Sequencing