Connexin 26 (GJB2) Sequencing and Deletion/Duplication
Also known as: CX26 NGS
Use
This test is used for diagnostic testing or carrier screening for GJB2-related nonsyndromic hearing loss (NSHL). It can be used as a first-tier genetic test for individuals with severe-to-profound congenital NSHL. Pathogenic germline variants in the GJB2 gene are associated with autosomal recessive deafness type 1A (DFNB1A), characterized by mild to profound nonsyndromic hearing loss that is typically nonprogressive.
Special Instructions
Informed consent for genetic testing is required for patients from New York. Specimens from New York clients will be sent to a New York state-approved laboratory. Provide patient history form for hearing loss testing.
Limitations
The test only detects variants within the coding regions, intron-exon boundaries, and selected noncoding variants of the GJB2 gene. Deletions/duplications/insertions of any size may not be detected by massively parallel sequencing. Regulatory region variants and deep intronic variants will not be identified. Mosaic or somatic variants, gene conversion events, complex inversions, translocations, and mitochondrial DNA variants are not intended to be detected. Diagnostic errors can occur due to rare sequence variations.
Methodology
NGS (Targeted)
Biomarkers
LOINC Codes
- 66746-9
- 90851-7
Result Turnaround Time
10-15 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
3 mL
Container
Lavender or pink (EDTA) or yellow (ACD solution A or B)
Causes for Rejection
Serum or plasma; grossly hemolyzed or frozen specimens; saliva, buccal brush, or swab; FFPE tissue.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 1 week |
| Frozen | Unacceptable |