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Specialized Sequencing of the Mutational Hotspot RPGR (isoform C) ORF15 Region

Summary and Pricing

Test Method

Bi-Directional Sanger Sequencing
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
2085 RPGR 81479 81479 $440 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
2085RPGR81479 81479 $440 Order Options and Pricing

Pricing Comments

CNV detection may be ordered through Test #600.

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

Turnaround Time

12 days on average for standard orders or 8 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

  • Dana Talsness, PhD

Clinical Features and Genetics

Clinical Features

Retinitis Pigmentosa (RP) refers to a group of related eye disorders stemming from the degeneration of photoreceptor cells in the retina (Fahim et al. 1993. PubMed ID: 20301590). RP derives its name from retinal pigmentation changes. In RP patients, pigment granules accumulate in perivascular clusters, called bone-spicules, in the retinal pigment epithelium (RPE). The accumulation of pigment is typically accompanied by death of the photoreceptor cells, first rods and eventually cones. As a result, RP will often present first with night blindness and decreased peripheral vision due to systematic loss of rod cells, followed by deterioration of central vision acuity and day blindness from the loss of cone cells. RP has an incidence of ~1/3500 and can be inherited in autosomal recessive, autosomal dominant, X-linked, oligogenic and even mitochondrial patterns. Currently, pathogenic variants in over 80 genes are known to cause RP (van Soest et al. 1999. PubMed ID: 10025514).

Genetics

X-linked Retinitis pigmentosa (XLRP) is one of the most severe forms of RP, with early onset and rapid progression in males. Milder symptoms can also present in females, probably due to skewed X inactivation. At least five different genetic loci have been associated with XLRP: Xp11.2 (RP2), Xp21.1 (RPGR), Xp21.2-21.3 (RP6), Xp22 (RP23) and Xp26-27 (RP24) (http://www.sph.uth.tmc.edu/RetNet/disease.htm). To date, only the RPGR, RP2 and OFD1 genes have been identified.

RPGR encodes the retinitis pigmentosa GTPase regulator, a photoreceptor ciliary protein that is essential for photoreceptor survival (Meindl et al. 1996. PubMed ID: 8673101). Pathogenic variants in RPGR account for the vast majority (~80%) of all XLRP cases, (Sharon et al. 2003. PubMed ID: 14564670; Vervoort et al. 2000. PubMed ID: 10932196). The RPGR gene encodes several alternatively spliced isoforms, although Retinitis pigmentosa causative variants are only found in isoform C. Isoform C consists of 15 coding exons, with exon 15 (usually referred to as ORF15; see Bader et al. 2003. PubMed ID: 12657579 for a detailed description of ORF15) coding for nearly 50% of the protein and it is glutamic acid rich region. Pathogenic variants in exons 1-14 account for less than 25% of XLRP cases. Purine rich ORF15 accounts for ~50-60% of XLRP patients (Vervoort et al. 2000. PubMed ID: 10932196; Shu et al. 2007. PubMed ID: 17195164; Sharon et al. 2003. PubMed ID: 14564670). Of note, pathogenic variants in RPGR account for other retinal dystrophies (such as X-linked cone rod dystrophy) and syndromal retinal dystrophies with ciliary dyskinesia and hearing loss (Yang et al. 2002. PubMed ID:11875055). The great majority of the pathogenic variants (63%) are small frameshift deletion/duplications that lead to protein termination, although missense, nonsense, large deletions/duplications and complex genomic rearrangements have been documented (Human Gene Mutation Database).

Clinical Sensitivity - Sanger Sequencing

This test is predicted to detect a causative mutation in ~70-80% of all patients with presumptive X-Linked Retinitis Pigmentosa (Sharon et al. 2003. PubMed ID: 14564670), or ~65% of patients with X-linked cone dystrophy (2 /3 families) (Demirci et al. 2002. PubMed ID: 11857109). The sensitivity for X-linked atrophic macular degeneration is unknown.

Testing Strategy

This test involves Sanger sequencing of the RPGR ORF15 region.

Indications for Test

This test is for patients with probable X-linked recessive RPGR-associated disorders.

Gene

Official Gene Symbol OMIM ID
RPGR 312610
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Related Tests

Name
RLBP1-Related Disorders via the RLBP1 Gene
Primary Ciliary Dyskinesia (PCD) via the RPGR Gene
Retinitis Pigmentosa (includes RPGR ORF15) Panel
X-linked Retinitis Pigmentosa (XLRP) via the RPGR (includes ORF15) Gene

Citations

  • Bader et al. 2003. PubMed ID: 12657579
  • Demirci et al. 2002. PubMed ID: 11857109
  • Fahim et al. 1993. PubMed ID: 20301590
  • Fahim et al. 2017. PubMed ID: 20301590
  • http://www.sph.uth.tmc.edu/RetNet/disease.htm
  • Human Gene Mutation Database (Bio-base).
  • Meindl et al. 1996. PubMed ID: 8673101
  • Meindl et al. 1996. PubMed ID: 8673101
  • Sharon et al. 2003. PubMed ID: 14564670
  • Shu et al. 2007. PubMed ID: 17195164
  • van Soest et al. 1999. PubMed ID: 10025514
  • Vervoort et al. 2000. PubMed ID: 10932196
  • Yang et al. 2002. PubMed ID:11875055

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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