Cone-Rod Dystrophy Panel

Summary and Pricing

Test Method

Exome Sequencing with CNV Detection
Test Code Test Copy Genes Gene CPT Codes Copy CPT Codes
10403 ABCA4 81408,81479 Order Options and Pricing
ADAM9 81479,81479
AIPL1 81479,81479
BEST1 81406,81479
CABP4 81479,81479
CACNA1F 81479,81479
CACNA2D4 81479,81479
CDHR1 81479,81479
CERKL 81479,81479
CFAP410 81479,81479
CFAP418 81479,81479
CNGB3 81479,81479
CNNM4 81479,81479
CRX 81404,81479
DRAM2 81479,81479
GUCA1A 81479,81479
GUCY2D 81479,81479
KCNV2 81479,81479
PDE6C 81479,81479
PDE6H 81479,81479
PITPNM3 81479,81479
POC1B 81479,81479
PROM1 81479,81479
PRPH2 81404,81479
RAB28 81479,81479
RAX2 81479,81479
RDH5 81479,81479
RGS9 81479,81479
RGS9BP 81479,81479
RIMS1 81479,81479
RPGR 81479,81479
RPGRIP1 81479,81479
SEMA4A 81479,81479
TTLL5 81479,81479
UNC119 81479,81479
Test Code Test Copy Genes Panel CPT Code Gene CPT Codes Copy CPT Code Base Price
10403Genes x (35)81479 81404, 81406, 81408, 81479 $890 Order Options and Pricing

Pricing Comments

We are happy to accommodate requests for testing single genes in this panel or a subset of these genes. The price will remain the list price. If desired, free reflex testing to remaining genes on panel is available. Alternatively, a single gene or subset of genes can also be ordered via our PGxome Custom Panel tool.

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

For Reflex to PGxome pricing click here.

Turnaround Time

18 days on average for standard orders or 14 days on average for STAT orders.

Once a specimen has started the testing process in our lab, the most accurate prediction of TAT will be displayed in the myPrevent portal as an Estimated Report Date (ERD) range. We calculate the ERD for each specimen as testing progresses; therefore the ERD range may differ from our published average TAT. View 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

Clinical Features and Genetics

Clinical Features

Cone-rod dystrophy (CORD/CRD) is a rare hereditary retinal disorder with a worldwide prevalence of ~1 in 40,000. CRD is characterized by dysfunction or degeneration of cone photoreceptors with relative preservation of rod function in the initial stages. The most common symptoms are photophobia and epiphora in bright light, decreased visual acuity, and dyschromatopsia. Fundus changes may vary from mild pigment granularity to a distinct atrophic lesion in the central macula. As the disease progresses, degeneration of rod photoreceptors also occurs and leads to progressive night blindness and peripheral visual field loss (Hamel. 2007. PubMed ID: 17270046).

Genetics

Non syndromic CRD is genetically heterogeneous and exhibits autosomal dominant (AD), autosomal recessive (AR) and, rarely, X-linked (XL) inheritance (Hamel. 2007. PubMed ID: 17270046). To date, over 25 genes have been implicated in different forms of CRD (RetNet). Causative variants in the genes ABCA4, ADAM9, AIPL1, CFAP410, C8orf37, CABP4, CACNA2D4, CDHR1, CERKL, CNGB3, CNNM4, DRAM2, KCNV2, PDE6C, POC1B, RAB28, RPGRIP1, RGS9, RGS9BP and TTLL5 are inherited in an AR manner. Causative variants in the genes CRX, GUCA1A, GUCY2D, PITPNM3, RAX2, RIMS1, SEMA4A, UNC119 show AD inheritance. Pathogenic variants in BEST1, PDE6H, PROM1 and PRPH2 are inherited in both autosomal dominant and recessive manner. CACNA1F and RPGR are the only genes associated with XL-CRD in male patients. Females are often but not always asymptomatic, possibly due to random X inactivation. RPGR is a major gene responsible for ~70% of the XL- Retinitis pigmentosa (RP) cases. Currently, its contribution to the XL-CRD is unknown (Hamel. 2007. PubMed ID: 17270046). RPGR gene open reading frame 15 (ORF15) sequence analysis is not included in this panel. Due to the genetic heterogeneity, screening of all the CRD-associated genes is recommended. Most of the CRD-associated genes are also involved in other types of retinal dystrophies such as RP, macular dystrophies and cone dystrophies. Many of these genes encode proteins that have major roles in disc morphogenesis and the membrane- trafficking of photoreceptors (Sung and Chuang. 2010. PubMed ID: 20855501).

See individual gene test descriptions for further information on molecular biology of gene products and mutation spectra.

Clinical Sensitivity - Sequencing with CNV PGxome

A mutation spectrum analysis by Sanger sequencing of eight autosomal dominant (AD) Cone-Rod Dystrophy (CRD) associated genes identified pathogenic variations in ~50% of all AD CD (cone dystrophy) and AD CRD cases (Kohl et al. 2012. PubMed ID: 22183351). Causative variants were identified in GUCY2D (23%), PRPH2 (11%), GUCA1A (8%), CRX (4%), and PROM1 (2%). No pathogenic variants were detected in AIPL1, UNC119 and PITPNM3, suggesting they may have a minor role in AD CD and AD CRD . A study based on literature searches (RetNet) reports that the autosomal recessive Cone-Rod Dystrophy (AR CRD) genes ABCA4, RPGRIP1, ADAM9 and CERKL are responsible for nearly 40% of AR CRD cases, ABCA4 being the major causative gene (den Hollander et al. 2010. PubMed ID: 20811160). Whole exome sequencing in 47 Chinese Families with CRD identified 14 potential pathogenic variations in 10 families (21.3%). These causative sequence variations were found in 6 of the 25 CRD-associated genes: CNGB3 (6.4%), PDE6C (4.3%), RPGR (4.3%), ABCA4 (2.0%), RPGRIP1 (2.0%), and CACNA1F (2.0%). The authors report that this is the first systemic exome-sequencing analysis of all 25 CRD-associated genes (Huang et al. 2013. PubMed ID: 23776498). All these genes together account for only about half of the ad/ar CRD cases, which indicates that there are still many genes that need to be identified (Hamel. 2007. PubMed ID: 17270046).

Gross deletions/duplications have been reported in BEST1, PRPH2, CRX, CNGB3, ABCA4, GUCY2D, CACNA2D4, CNNM4, KCNV2, RGS9BP, RPGR, and CACNA1F (Human Gene Mutation Database).

Testing Strategy

This test is performed using Next-Gen sequencing with additional Sanger sequencing as necessary.

This panel typically provides 99.2% coverage of all coding exons of the genes 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 coverage as ≥20X NGS reads or Sanger sequencing. Exon 1 of CERKL, exon 15 in RPGR, exon 1 of RPGRIP1, and a region in RIMS1 exon 1 are not covered for technical reasons.

If one single suspected pathogenic variant is found in ABCA4, CERKL, or RPGRIP1, we will complete coverage of these genes using Sanger sequencing, which includes documented deep intronic variants in ABCA4.

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

Indications for Test

All patients with symptoms suggestive of Cone-rod dystrophy are candidates.

Related Test

Name
PGxome®

Citations

  • den Hollander et al. 2010. PubMed ID: 20811160
  • Hamel. 2007. PubMed ID: 17270046
  • Huang et al. 2013. PubMed ID: 23776498
  • Human Gene Mutation Database (Bio-base).
  • Kohl et al. 2012. PubMed ID: 22183351
  • RetNet: Genes and Mapped Loci Causing Retinal Diseases
  • Sung and Chuang. 2010. PubMed ID: 20855501

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.

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 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.

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