DNA icon

Leber Congenital Amaurosis and Retinitis Pigmentosa via the CRB1 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
4961 CRB1 81406 81406,81479 $640 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
4961CRB181406 81406,81479 $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

  • Dana Talsness, PhD

Clinical Features and Genetics

Clinical Features

Leber congenital amaurosis (LCA, OMIM 613835) and retinitis pigmentosa (RP, OMIM 268000) are inherited degenerative diseases of the retina. LCA is characterized by bilateral congenital blindness. RP is characterized by night blindness, with age of onset varying from childhood to middle age, progressing to constriction of the peripheral visual field and, eventually, to loss of central vision. Several clinical features of LCA overlap with those of RP. These include attenuated retinal vessels, abnormal electroretinographic (ERG) findings, and a variable amount of retinal pigmentation (Perrault et al. Nat Genet 14:461-464, 1996; Daiger et al. Arch Ophthalmol 125:151-158, 2007; Gu et al. J Med Genet 36:705-707, 1999). Both LCA and RP are clinically and genetically heterogeneous.

Genetics

LCA is inherited as an autosomal recessive trait in the vast majority of patients, while RP is either sporadic or familial with various modes of Mendelian, mitochondrial, or digenic inheritance. To date, 14 genes have been implicated in LCA and 25 in autosomal recessive RP (AR-RP; den Hollander et al. Prog Retin Eye Res 27:391-419, 2008; Daiger et al. Arch Ophthalmol 125:151-158, 2007). The clinical overlap between LCA and RP is illustrated by the involvement of six genes in both conditions. These include the CRB1 gene. CRB1 variants were first identified in patients with a severe form of AR-RP characterized by preservation of the para-arteriolar retinal pigment epithelium (PPRPE) (RP12, OMIM 600105) (den Hollander et al. Nat Genet 23:217-221, 1999). Subsequently, CRB1 variants were reported in patients with LCA (Lotery et al. Arch Ophthalmol 119: 415-420, 2001). Over 40 different CRB1 variants have been reported in patients with LCA and 32 in RP. These variants include missense, nonsense, splicing, and small deletions/insertions. In addition to LCA and RP12, CRB1 variants were found in rare cases with severe AR-RP without PPRPE (Lotery et al. Ophthalmic Genet 22:163-169, 2001; Booij et al. J Med Genet 42:e67, 2005) and in one family with a history of autosomal dominant pigmented paravenous chorioretinal atrophy (PPCRA, OMIM 172870) (McKay et al. Invest Ophthalmol Vis Sci 46: 322-328, 2005). The CRB1 protein is expressed specifically in human retina and brain.

Clinical Sensitivity - Sequencing with CNV PG-Select

CRB1 variants account for ~ 15 % of patients with LCA (Yzer et al. Invest Ophthalmol Vis Sci 47:1167-1176, 2006), 6.5% of patients with AR-RP (Bernal et al. J Med Genet 40:e89, 2003) and up to 50% of patients with AR-RP and PPRPE (den Hollander et al. Hum Mutat 24:355-369, 2004).

Testing Strategy

This test provides full coverage of all coding exons of the CRB1 gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.

Indications for Test

All patients with LCA and with early-onset RP are candidates. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in CRB1.

Gene

Official Gene Symbol OMIM ID
CRB1 604210
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Related Tests

Name
Leber Congenital Amaurosis 4 (LCA4) via the AIPL1 Gene
Leber Congenital Amaurosis Panel
Retinitis Pigmentosa (includes RPGR ORF15) Panel

Citations

  • Bernal, S., et.al. (2003). "Study of the involvement of the RGR, CRPB1, and CRB1 genes in the pathogenesis of autosomal recessive retinitis pigmentosa." J Med Genet 40(7): e89. PubMed ID: 12843338
  • Booij JC. 2005. Identification of mutations in the AIPL1, CRB1, GUCY2D, RPE65, and RPGRIP1 genes in patients with juvenile retinitis pigmentosa. Journal of Medical Genetics 42: e67–e67. PubMed ID: 16272259
  • Daiger et al. 2007. PubMed ID: 17296890
  • den Hollander AI, Roepman R, Koenekoop RK, Cremers FPM. 2008. Leber congenital amaurosis: genes, proteins and disease mechanisms. Prog Retin Eye Res 27: 391–419. PubMed ID: 18632300
  • den Hollander, A. I., et.al. (1999). "Mutations in a human homologue of Drosophila crumbs cause retinitis pigmentosa (RP12)." Nat Genet 23(2): 217-21. PubMed ID: 10508521
  • den Hollander, A. I., et.al. (2004). "CRB1 mutation spectrum in inherited retinal dystrophies." Hum Mutat 24(5): 355-69. PubMed ID: 15459956
  • Gu S. et al. 1999. Journal of Medical Genetics. 36: 705-7. PubMed ID: 10507729
  • Lotery, A. J., et.al. (2001). "CRB1 mutations may result in retinitis pigmentosa without para-arteriolar RPE preservation." Ophthalmic Genet 22(3): 163-9. PubMed ID: 11559858
  • Lotery, A. J., et.al. (2001). "Mutations in the CRB1 gene cause Leber congenital amaurosis." Arch Ophthalmol 119(3): 415-20. PubMed ID: 11231775
  • McKay, G. J., et.al. (2005). "Pigmented paravenous chorioretinal atrophy is associated with a mutation within the crumbs homolog 1 (CRB1) gene." Invest Ophthalmol Vis Sci 46(1): 322-8. PubMed ID: 15623792
  • Perrault I, Rozet JM, Calvas P, Gerber S, Camuzat A, Dollfus H, Châtelin S, Souied E, Ghazi I, Leowski C, Bonnemaison M, Paslier D Le, et al. 1996. Retinal-specific guanylate cyclase gene mutations in Leber’s congenital amaurosis. Nat. Genet. 14: 461–464. PubMed ID: 8944027
  • Yzer, S., et.al. (2006). "Microarray-based mutation detection and phenotypic characterization of patients with Leber congenital amaurosis." Invest Ophthalmol Vis Sci 47(3): 1167-76. PubMed ID: 16505055

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

loading Loading... ×

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: $
×
Copy Text to Clipboard
×