Deafness, Autosomal Dominant 51 (DFNA51) via the TJP2 Gene
Summary and Pricing
Test Method
Sequencing and CNV Detection via NextGen Sequencing using PG-Select Capture ProbesTest Code | Test Copy Genes | Test CPT Code | Gene CPT Codes Copy CPT Code | Base Price | |
---|---|---|---|---|---|
15401 | TJP2 | 81479 | 81479,81479 | $990 | Order Options and Pricing |
Pricing Comments
Testing run on PG-select capture probes includes CNV analysis for the gene(s) on the panel but does not permit the optional add on of exome-wide CNV analysis. Any of the NGS platforms allow reflex to other clinically relevant genes, up to whole exome or whole genome sequencing depending upon the base platform selected for the initial test.
An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.
This test is also offered via a custom panel (click here) on our exome or genome backbone which permits the optional add on of exome-wide CNV or genome-wide SV analysis.
Turnaround Time
3 weeks on average for standard orders or 2 weeks on average for STAT orders.
Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.
Targeted Testing
For ordering sequencing of targeted known variants, go to our Targeted Variants page.
Clinical Features and Genetics
Clinical Features
Autosomal dominant deafness 51 (DFNA51) is a postlingual, bilateral, progressive, nonsyndromic, sensorineural hearing loss disorder. Initial onset ranges from the second to sixth decade of life involving high frequencies and progressing to severe to profound at all frequencies (Walsh et al. 2010; Wang et al. 2015).
Genetics
DFNA51 is an autosomal dominant hearing disorder that is caused by pathogenic sequence variants in the tight junction protein 2 (TJP2) gene, which is located on chromosome 9q21.11 (Walsh et al. 2010; Kim et al. 2014). The TJP2 gene spans 81 kb and consists of 23 coding exons that produce a 1,190-amino acid protein that is a component of the tight junction barrier in epithelial and endothelial cells. In the mouse inner ear the TJP2 protein is localized in membranes connecting hair cells and supporting cells in the cochlea and is also expressed in cells of the vestibular system (Walsh et al. 2010).
The 4 TJP2 variants implicated to date in hearing loss consist of 3 missense (Kim et al. 2014; Wang et al. 2015) and 1 large duplication encompassing the entire TJP2 gene (Walsh et al. 2010). Additional missense, splicing, small and large deletion variants in TJP2 have been shown to cause cholestatic liver disease and hypercholanaemia not associated with hearing loss (Human Gene Mutation Database).
Clinical Sensitivity - Sequencing with CNV PG-Select
Pathogenic sequence variants in TJP2 have been reported to cause autosomal dominant nonsyndromic hearing loss in three Korean families and one Chinese family (Kim et al. 2014; Wang et al. 2015). Due to the limited number of known pathogenic variants the sensitivity of this test is currently unknown.
Only a single pathogenic copy number variant in TJP2 has been documented in association with autosomal dominant nonsyndromic hearing loss in a single family of Jewish ancestry (Walsh et al. 2010).
Testing Strategy
This test is performed using Next-Gen sequencing with additional Sanger sequencing as necessary.
This test provides full coverage of all coding exons of the TJP2 gene plus 10 bases of flanking noncoding DNA in all available transcripts along with other non-coding regions in which pathogenic variants have been identified at PreventionGenetics or reported elsewhere. We define full coverage as >20X NGS reads or Sanger sequencing.
Indications for Test
Patients with 1) postlingual, mild to profound, progressive sensorineural hearing impairment, 2) no related systemic findings identified by medical history and physical examination and/or 3) a family history of nonsyndromic hearing loss consistent with autosomal dominant inheritance.
Patients with 1) postlingual, mild to profound, progressive sensorineural hearing impairment, 2) no related systemic findings identified by medical history and physical examination and/or 3) a family history of nonsyndromic hearing loss consistent with autosomal dominant inheritance.
Gene
Official Gene Symbol | OMIM ID |
---|---|
TJP2 | 607709 |
Inheritance | Abbreviation |
---|---|
Autosomal Dominant | AD |
Autosomal Recessive | AR |
X-Linked | XL |
Mitochondrial | MT |
Disease
Name | Inheritance | OMIM ID |
---|---|---|
Deafness, Autosomal Dominant 51 | AD | 613558 |
Citations
Ordering/Specimens
Ordering Options
We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.
myPrevent - Online Ordering
- The test can be added to your online orders in the Summary and Pricing section.
- Once the test has been added log in to myPrevent to fill out an online requisition form.
- PGnome sequencing panels can be ordered via the myPrevent portal only at this time.
Requisition Form
- A completed requisition form must accompany all specimens.
- Billing information along with specimen and shipping instructions are within the requisition form.
- All testing must be ordered by a qualified healthcare provider.
For Requisition Forms, visit our Forms page
If ordering a Duo or Trio test, the proband and all comparator samples are required to initiate testing. If we do not receive all required samples for the test ordered within 21 days, we will convert the order to the most effective testing strategy with the samples available. Prior authorization and/or billing in place may be impacted by a change in test code.
Specimen Types
ORDER OPTIONS
View Ordering Instructions1) Select Test Type
2) Select Additional Test Options
No Additional Test Options are available for this test.