Connexin 26 (GJB2), Sequencing
0051374
Ordering Recommendation
Diagnostic testing for GJB2-related nonsyndromic hearing loss.  Carrier screening for GJB2-related nonsyndromic hearing loss.
Mnemonic
CX26SEQ
Methodology
Polymerase Chain Reaction/Sequencing
Performed
Varies
Reported
Within 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.





See Compliance Statement C: www.aruplab.com/CS
Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test; however, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
 
Note
 
CPT Code(s)
81252
Components
Component Test Code*Component Chart NameLOINC
0051375Connexin 26, Full Gene Sequencing35300-3
2001348CX26SEQ 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