DNA icon

Cone-Rod Dystrophy via the CDHR1 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
CDHR1 81479 81479,81479 $990
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
11165CDHR181479 81479,81479 $990 Order Options and Pricing

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.

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 platform).

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

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

For Sanger Sequencing click here.

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.


Genetic Counselors


  • Dana Talsness, PhD

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).


Non syndromic CRD is genetically heterogeneous and exhibits autosomal dominant (ad), autosomal recessive (ar) and, rarely, X-linked (xl) inheritance (Hamel 2007). So far, about 25 genes have been implicated in different forms of CRD (RetNet). CDHR1 (Cadherin-related family member 1) gene located on chromosome 10q23.1, is involved with arCRD. CDHR1 (previously known as PCDH21) encodes a cadherin, a structural, transmembrane protein highly expressed in the retinal photoreceptor cells. Specifically, CDHR1 is localized to the base of the rod and cone outer segments (OSs) and involved in in the structural integrity of the OS and photoreceptor survival (Rattner et al. 2001; Ba-Abbad et al. 2013; Duncan et al. 2012; Cohen et al. 2011; Ostergaard et al. 2010). It has also been reported that the CDHR1 protein co-localizes with Prominin 1(PROM1) a pentaspan transmembrane glycoprotein. Both proteins have been reported to be involved in disc morphogenesis (Henderson et al. 2010). Cadherins have extracellular cadherin (EC) domains, which comprises highly conserved Ca2+ binding motifs that are often involved in calcium-dependent cell adhesion (Cohen et al. 2011). Interestingly, along with CDHR1, three other genes that belong to the cadherin family are related to retinal degenerations (CDH23, PCDH15, CDH3) (Bolz et al. 2005). There are about ten known pathogenic variations in CDHR1 which are associated with autosomal recessive cone-rod dystrophy (Human Gene Mutation Database).

Clinical Sensitivity - Sequencing with CNV PGxome

Sequencing of CDHR1 detected homozygous mutations in all affected members (3 male and 2 female) of two families. The parents were heterozygous for the mutations (Henderson et al. 2010), which were not detected in over 280 control chromosomes. In two different studies, three affected siblings and six CRD patients in a consanguineous family from Faroe Islands had homozygous CDHR1 mutations (Ba-Abbad et al. 2013; Ostergaard et al. 2010). CDHR1 mutations have only been reported in individual families. All reported mutations are detectable by sequencing. No gross deletions or duplications have been reported.

Testing Strategy

This test provides full coverage of all coding exons of the CDHR1 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. 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 Cone-rod dystrophy. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in CDHR1.


Official Gene Symbol OMIM ID
CDHR1 609502
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT


Name Inheritance OMIM ID
Cone-Rod Dystrophy 15 AR 613660


  • Ba-Abbad R, Sergouniotis PI, Plagnol V, Robson AG, Michaelides M, Holder GE, Webster AR. 2013. Clinical characteristics of early retinal disease due to CDHR1 mutation. Molecular vision 19: 2250. PubMed ID: 24265541
  • Bolz H, Ebermann I, Gal A. 2005. Protocadherin-21 (PCDH21), a candidate gene for human retinal dystrophies. Mol Vis 11: 92933. PubMed ID: 16288196
  • Cohen B, Chervinsky E, Jabaly-Habib H, Shalev SA, Briscoe D, Ben-Yosef T. 2011. A novel splice site mutation of CDHR1 in a consanguineous Israeli Christian Arab family segregating autosomal recessive cone-rod dystrophy. Molecular vision 18: 29152921. PubMed ID: 23233793
  • Duncan JL, Roorda A, Navani M, Vishweswaraiah S, Syed R, Soudry S, Ratnam K, Gudiseva HV, Lee P, Gaasterland T, Ayyagari R. 2012. Identification of a Novel Mutation in the CDHR1 Gene in a Family With Recessive Retinal Degeneration. Archives of Ophthalmology 130: 1301. PubMed ID: 23044944
  • Hamel CP. 2007. Cone rod dystrophies. Orphanet J Rare Dis 1;2:7. PubMed ID: 17270046
  • Henderson RH, Li Z, El Aziz MM Abd, Mackay DS, Eljinini MA, Zeidan M, Moore AT, Bhattacharya SS, Webster AR. 2010. Biallelic mutation of protocadherin-21 (PCDH21) causes retinal degeneration in humans. Mol. Vis. 16: 4652. PubMed ID: 20087419
  • Human Gene Mutation Database (Bio-base).
  • Ostergaard E, Batbayli M, Duno M, Vilhelmsen K, Rosenberg T. 2010. Mutations in PCDH21 cause autosomal recessive cone-rod dystrophy. Journal of Medical Genetics 47: 665669. PubMed ID: 20805371
  • Rattner A, Smallwood PM, Williams J, Cooke C, Savchenko A, Lyubarsky A, Pugh EN, Nathans J. 2001. A photoreceptor-specific cadherin is essential for the structural integrity of the outer segment and for photoreceptor survival. Neuron 32: 775786. PubMed ID: 11738025


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

If ordering a Duo or Trio test, the proband and all comparator samples are required to initiate testing. If we do not receive all required samples for the test ordered within 21 days, we will convert the order to the most effective testing strategy with the samples available. Prior authorization and/or billing in place may be impacted by a change in test code.

Specimen Types

Specimen Requirements and Shipping Details

PGxome (Exome) Sequencing Panel

PGnome (Genome) Sequencing Panel

loading Loading... ×


An error has occurred while calculating the price. Please try again or contact us for assistance.

View Ordering Instructions

1) Select Test Method (Platform)

1) Select Test Type

2) Select Additional Test Options

No Additional Test Options are available for this test.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
Total Price: loading
Patient Prompt Pay Price: loading
A patient prompt pay discount is available if payment is made by the patient and received prior to the time of reporting.
Show Patient Prompt Pay Price
Copy Text to Clipboard