Classic view of this page
GJB2-Related DFNB 1 Nonsyndromic Hearing Loss and Deafness
Clinical Genetic Test
Help
offered by
Molecular Genetics Laboratory
View lab's test page
LinkOut
GTR Test Accession: Help GTR000073172.3
Last updated in GTR: 2023-02-08
View version history
At a Glance
Test purpose: Help
Mutation Confirmation; Diagnosis
Conditions (1): Help
Autosomal recessive nonsyndromic hearing loss 1A
Genes (2): Help
GJB2 (13q12.11), GJB6 (13q12.11)
Methods (3): Help
Molecular Genetics - Deletion/duplication analysis: Next-Generation (NGS)/Massively parallel sequencing (MPS); PCR; ...
Target population: Help
Diagnosis of DFNB1 depends on molecular genetic testing to identify …
Clinical validity: Help
Diagnosis of DFNB1 depends on molecular genetic testing to identify …
Clinical utility: Help
Establish or confirm diagnosis
Ordering Information
Offered by: Help
Molecular Genetics Laboratory
View lab's website
View lab's test page
Specimen Source: Help
Who can order: Help
  • Genetic Counselor
  • Licensed Physician
Test Order Code: Help
Non Syndromic Recessive Deafness
Lab contact: Help
Alan Stuart, BSc, Administrator
alan.stuart@lhsc.on.ca
519-685-8122
Contact Policy: Help
Laboratory can only accept contact from health care providers. Patients/families are encouraged to discuss genetic testing options with their health care provider.
How to Order: Help
Please complete the requisition found on the website and ensure it is signed by the referring physician
Order URL
Test service: Help
Clinical Testing/Confirmation of Mutations Identified Previously
Confirmation of research findings
Custom Deletion/Duplication Testing
Test additional service: Help
Custom mutation-specific/Carrier testing
Custom Prenatal Testing
Test development: Help
Test developed by laboratory (no manufacturer test name)
Informed consent required: Help
Decline to answer
Test strategy: Help
Full sequence analysis of GJB2(Cx26) and GJB6(Cx30) complemented by deletion/duplication analysis of GJB6(Cx30) and GJB2(Cx26).
Pre-test genetic counseling required: Help
Decline to answer
Post-test genetic counseling required: Help
Decline to answer
Conditions Help
Total conditions: 1
Condition/Phenotype Identifier
Test Targets
Genes Help
Total genes: 2
Gene Associated Condition Germline or Somatic Allele (Lab-provided) Variant in NCBI
Methodology
Total methods: 3
Method Category Help
Test method Help
Instrument
Deletion/duplication analysis
Next-Generation (NGS)/Massively parallel sequencing (MPS)
Illumina MiSeq/NextSeq
Deletion/duplication analysis
PCR
Sequence analysis of the entire coding region
Next-Generation (NGS)/Massively parallel sequencing (MPS)
Illumina MiSeq/NextSeq
Clinical Information
Test purpose: Help
Mutation Confirmation; Diagnosis
Clinical validity: Help
Diagnosis of DFNB1 depends on molecular genetic testing to identify deafness-causing mutations in GJB2 and/or GJB6 that alter the gap junction beta-2 protein (connexin 26) and the gap junction beta-6 protein (connexin 30), respectively. Clinically available molecular genetic testing of GJB2 and GJB6 detects more than 99% of deafness-causing mutations … View more
View citations (2)
  • Smith RJH, Azaiez H, Booth K. -Related Autosomal Recessive Nonsyndromic Hearing Loss. 1998 Sep 28 [updated 2023 Jul 20]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. PMID: 20301449.
  • https://www.ncbi.nlm.nih.gov/books/NBK1272
Clinical utility: Help
Establish or confirm diagnosis
View citations (1)

Target population: Help
Diagnosis of DFNB1 depends on molecular genetic testing to identify deafness-causing mutations in GJB2 and/or GJB6 that alter the gap junction beta-2 protein (connexin 26) and the gap junction beta-6 protein (connexin 30), respectively. Clinically available molecular genetic testing of GJB2 and GJB6 detects more than 99% of deafness-causing mutations … View more
View citations (1)
  • Smith RJH, Azaiez H, Booth K. -Related Autosomal Recessive Nonsyndromic Hearing Loss. 1998 Sep 28 [updated 2023 Jul 20]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. PMID: 20301449.
Variant Interpretation:
What is the protocol for interpreting a variation as a VUS? Help
Novel variations are interrogated using a series of tools. Literature reviews and a search of relevant databases and dbSNP is pursued. This is followed by evaluation using web based insilco analysis including, but not restricted to SIFT, Polyphen2, AlignGVGD, SNPs&GO and ASSEDA(splice). If the pathogenicity is still indeterminate (ACMG group … View more

Will the lab re-contact the ordering physician if variant interpretation changes? Help
Not provided.
Recommended fields not provided:
Are family members with defined clinical status recruited to assess significance of VUS without charge?, Will the lab re-contact the ordering physician if variant interpretation changes?, Is research allowed on the sample after clinical testing is complete?, Sample negative report, Sample positive report
Technical Information
Test Procedure: Help
Mutations identified are repeated in an independent assay
Test Confirmation: Help
Mutations identified are repeated in an independent assay
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
Sensitivity of this methodology is predicted to be >99%
View citations (1)
  • Schenkel LC, Kerkhof J, Stuart A, Reilly J, Eng B, Woodside C, Levstik A, Howlett CJ, Rupar AC, Knoll JHM, Ainsworth P, Waye JS, Sadikovic B. Clinical Next-Generation Sequencing Pipeline Outperforms a Combined Approach Using Sanger Sequencing and Multiplex Ligation-Dependent Probe Amplification in Targeted Gene Panel Analysis. J Mol Diagn. 2016;18(5):657-667. doi:10.1016/j.jmoldx.2016.04.002. Epub 2016 Jul 02. PMID: 27376475.
Proficiency testing (PT):
Is proficiency testing performed for this test? Help
No
VUS:
Software used to interpret novel variations Help
ALAMUT, integrating other programs (Polyphen-2, Mutation Taster, Alignment, ExPASy, BLAST)

Laboratory's policy on reporting novel variations Help
All variants interpreted as either ACMG category 1, 2, or 3 (pathogenic, likely pathogenic, VUS; PMID: 25741868) are confirmed using Sanger sequencing, MLPA, or other assays. ACMG category 4 and 5 variants (likely benign, benign) are not reported, but are available upon request.
Recommended fields not provided:
Assay limitations, Description of internal test validation method, PT Provider, Description of PT method, Major CAP category, CAP category, CAP test list
Regulatory Approval
FDA Review: Help
Category: FDA exercises enforcement discretion
Additional Information

IMPORTANT NOTE: NIH does not independently verify information submitted to GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.