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Bradyopsia (Retinal Dysfunction) via the RGS9 Gene

Summary and Pricing

Test Method

Exome Sequencing with CNV Detection
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
13029 RGS9 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
13029RGS981479 81479,81479 $890 Order Options and Pricing

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

Click here for costs to reflex to whole PGxome (if original test is on PGxome Sequencing backbone).

Click here for costs to reflex to whole PGnome (if original test is on PGnome Sequencing backbone).

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.

EMAIL CONTACTS

Genetic Counselors

Geneticist

  • Dana Talsness, PhD

Clinical Features and Genetics

Clinical Features

Bradyopsia or RGS9/RGS9BP-associated retinopathy is a rare retinal dysfunction that is inherited in an autosomal recessive manner. It is clinically characterized by reduced central vision from childhood due to cone dysfunction, mild photophobia, normal color vision, lack of nystagmus, normal fundi and distinctive electrophysiologic features (Michaelides et al. 2010. PubMed ID: 19818506). The chief complaint of all patients was difficulty tracking moving objects and adapting to sudden changes in luminance levels. Walking out of a house into the sunlight for example causes temporary severe blindness (Kooijman et al. 1991. PubMed ID: 1790747).

With the advent of gene therapy and other types of treatments, the identification of causative genes and variants is becoming increasingly important.

Genetics

Pathogenic variants in either RGS9 (encoding a GTPase-activating protein) or RGS9BP (encoding its membrane anchor protein) have been identified in patients with autosomal recessive bradyopsia or RGS9/RGS9BP-associated retinopathy (Strauss et al. 2015. PubMed ID: 26343007). Both genes play a critical role in the recovery phase of visual transduction (Strauss et al. 2015. PubMed ID: 26343007; Nishiguchi et al. 2004. PubMed ID: 14702087). To date, less than 5 pathogenic variants (missense and nonsense) in RGS9 have been reported to cause bradyopsia (Michaelides et al. 2010. PubMed ID: 19818506; Nishiguchi et al. 2004. PubMed ID: 14702087; Human Gene Mutation Database). De novo variants have not been reported in either RGS9 or RGS9BP.

Mouse model studies suggested that RGS9 is required for normal inactivation of the cone phototransduction cascades (Lyubarsky et al. 2001. PubMed ID: 11262419). In both RGS9 and R9AP knockout mice, a small delay was observed in ON-bipolar cell light responses manifested as delayed onset of electroretinography b-waves. This is consistent with the prolonged electroretinal response suppression (PERRS) in the Bradyopsia patients (Herrmann et al. 2011. PubMed ID: 22096596; Kooijman et al. 1991. PubMed ID: 1790747).

Clinical Sensitivity - Sequencing with CNV PGxome

Predicting clinical sensitivity for the RGS9 gene is challenging due to genetic heterogeneity and the limited number of cases. All the documented causative variants are detectable by this NGS technology.

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 RGS9 gene plus 10 bases flanking noncoding DNA in all available transcripts in addition to 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. PGnome panels typically provide slightly increased coverage over the PGxome equivalent. PGnome sequencing panels have the added benefit of additional analysis and reporting of deep intronic regions (where applicable).

Dependent on the sequencing backbone selected for this testing, discounted reflex testing to any other similar backbone-based test is available (i.e., PGxome panel to whole PGxome; PGnome panel to whole PGnome).

Indications for Test

All patients with symptoms suggestive of bradyopsia are candidates. The term was proposed due to the the patients’ difficulty in adapting to changes in luminance. Targeted testing is indicated for family members of patients who have known pathogenic variants in RGS9. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in RGS9.

Gene

Official Gene Symbol OMIM ID
RGS9 604067
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Prolonged Electroretinal Response Suppression AR 608415

Citations

  • Herrmann et al. 2011. PubMed ID: 22096596
  • Human Gene Mutation Database (Bio-base).
  • Kooijman et al. 1991. PubMed ID: 1790747
  • Lyubarsky et al. 2001. PubMed ID: 11262419
  • Michaelides et al. 2010. PubMed ID: 19818506
  • Nishiguchi et al. 2004. PubMed ID: 14702087
  • Strauss et al. 2015. PubMed ID: 26343007

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

PGxome (Exome) Sequencing Panel

PGnome (Genome) Sequencing Panel

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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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