Hearing Loss, Nonsyndromic, Connexin 30 (GJB6) 2 Deletions
2001956
Ordering Recommendation
Diagnostic testing for GJB6-related nonsyndromic hearing loss. Carrier screening for GJB6-related nonsyndromic hearing loss.
Mnemonic
GJB6 DEL
Methodology
Polymerase Chain Reaction/Capillary Electrophoresis
Performed
Varies
Reported
2-7 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
Interpretive Data
Background Information for Hearing Loss, Nonsyndromic, Connexin 30 (GJB6) 2 Deletions:
Characteristics
: Moderate to profound nonsyndromic hearing loss (NSHL).
Incidence
: Approximately 1 in 30 individuals with NSHL has a GJB6 deletion; 1 in 100,000 in the general population.
Inheritance
: Autosomal recessive. Compound heterozygotes for GJB2 and GJB6 mutations are affected. Twenty percent of GJB2 heterozygotes with NSHL have a GJB6 deletion; homozygosity for GJB6 deletions is rare.
Cause
: GJB6 gene mutations.
Mutations Tested
: 309kb del(GJB6-D13S1830), previously reported as 342kb, and 232kb del(GJB6-D13S1854).
Clinical Sensitivity
: Dependent on ethnicity.
Clinical Specificity
: 99 percent.
Methodology
: Multiplex PCR using deletion-specific primers, followed by capillary gel electrophoresis.
Analytical Sensitivity and Specificity
: Greater than 99 percent.
Limitations
: GJB6 mutations other than the two targeted will not be identified. The etiology of hearing loss due to other genetic or environmental causes will not be determined. Diagnostic errors can occur due to rare sequence variations.



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS
Note
CPT Code(s)
81254
Components
Component Test Code*Component Chart Name
2001957Connexin 30 GJB6 Deletion 309
2001958GJB6 DEL Specimen Type
2001959Connexin 30 Interpretation
2002107Connexin 30 GJB6 Deletion 232
* 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.
Cross References
  • Connexin 30 mutation assay
  • GJB6
  • GJB6 deletions assay