Deafness-Dystonia-Optic Neuronopathy (Mohr-Tranebjaerg/Jensen) Syndrome via the TIMM8A Gene

Summary and Pricing

Test Method

Exome Sequencing with CNV Detection
Test Code Test Copy GenesPrice Test CPT CodeGene CPT Codes Copy CPT Codes STAT Prenatal
9091 TIMM8A$890 8147981479,81479 Add to Order

Pricing Comments

Our favored testing approach is exome based NextGen sequencing with CNV analysis. This will allow cost effective reflexing to PGxome or other exome based tests. However, if full gene Sanger sequencing is desired for STAT turnaround time, insurance, or other reasons, please see link below for Test Code, pricing, and turnaround time information. If the Sanger option is selected, CNV detection may be ordered through Test #600.

A 25% additional charge will be applied to STAT orders. View STAT turnaround times here.

For Reflex to PGxome pricing click here.

The Sanger Sequencing method for this test is NY State approved.

For Sanger Sequencing click here.

Targeted Testing

For ordering sequencing of targeted known variants, go to our Targeted Variants page.

Turnaround Time

18 days on average

EMAIL CONTACTS

Genetic Counselors

Geneticist

Clinical Features and Genetics

Clinical Features

Mohr-Tranebjaerg syndrome is an X-linked disorder characterized by males presenting with progressive prelingual or postlingual sensorineural hearing loss. Impaired hearing becomes evident between ages 2 to 5, with profound hearing loss typically presenting before age ten years. The deafness can be part of a progressive syndrome that includes visual disability leading to cortical blindness, dystonia, fractures, and mental deficiency and was later renamed as Deafness-Dystonia-Optic Neuronopathy (DDON) Syndrome (Tranebjaerg 2013). Opticoacoustic nerve atrophy (Jensen syndrome) [OMIM # 311150] and deafness-dystonia syndrome [OMIM # 304700] are the same as DDON syndrome.

Genetics

Mohr-Tranebjaerg syndrome is an X-linked recessive disorder of unknown prevalence with less than100 affected individuals identified worldwide. Some obligate carrier females show signs of minor neuropathy and mild hearing impairment. DDON or Mohr-Tranebjaerg syndrome occurs as either a single-gene disorder resulting from missense and nonsense mutations as well as small deletions in TIMM8A. It also occurs as a contiguous gene deletion syndrome at Xq22, which also includes X-linked agammaglobulinemia caused by disruption of BTK, located telomeric to TIMM8A.

Testing Strategy

This test provides full coverage of all coding exons of the TIMM8A 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.

Since this test is performed using exome capture probes, a reflex to any of our exome based tests is available (PGxome, PGxome Custom Panels).

Clinical Sensitivity - Sequencing with CNV

Since very limited studies have been done to evaluate this disorder, the clinical sensitivity of our assay is currently unknown.

Indications for Test

DDON syndrome is suspected in males with the following: progressive sensorineural hearing impairment with prelingual or postlingual onset, movement disorder (dystonia/ataxia), gradual onset and slow progression of personality changes, paranoia, dementia, gradual decrease in visual acuity associated with optic atrophy, gradual onset and slow progression of dysphagia and a family history consistent with X-linked recessive inheritance.

Gene

Official Gene Symbol OMIM ID
TIMM8A 300356
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Diseases

Name Inheritance OMIM ID
Jensen Syndrome 311150
Mohr-Tranebjaerg Syndrome XL 304700

Citations

  • Tranebjærg L. 2013. Deafness-Dystonia-Optic Neuronopathy Syndrome. In: Pagon RA, Adam MP, Bird TD, Dolan CR, Fong C-T, and Stephens K, editors. GeneReviews™, Seattle (WA): University of Washington, Seattle. PubMed ID: 20301395

Ordering/Specimens

Ordering Options

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.

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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