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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 Probes
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
15401 TJP2 81479 81479,81479 $640 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
15401TJP281479 81479,81479 $640 Order Options and Pricing

Pricing Comments

This test is also offered via our exome backbone with CNV detection (click here). The exome-based test may be higher priced, but permits reflex to the entire exome or to any other set of clinically relevant genes.

An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.

Turnaround Time

18 days on average for standard orders or 13 days 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.

EMAIL CONTACTS

Genetic Counselors

Geneticist

  • Ben Dorshorst, PhD

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.

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

  • Human Gene Mutation Database (HGMD).
  • Kim Min-A et al. 2014. Plos One. 9: e95646. PubMed ID: 24752540
  • Walsh T. et al. 2010. American Journal of Human Genetics. 87:101-9. PubMed ID: 20602916
  • Wang H.Y. et al. 2015. Chinese Medical Journal. 128:3345-51. PubMed ID: 26668150

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


Specimen Types

Specimen Requirements and Shipping Details

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ORDER OPTIONS

View Ordering Instructions

1) Select Test Method (Backbone)


1) Select Test Type


2) Select Additional Test Options

STAT and Prenatal Test Options are not available with Patient Plus.

No Additional Test Options are available for this test.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
Total Price: $
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