National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Cone-rod dystrophy 2



Other Names:
CORD2; Cone-rod retinal dystrophy 2; CRD2; CORD2; Cone-rod retinal dystrophy 2; CRD2; Retinal cone-rod dystrophy 2; RCRD2 See More
Categories:
This disease is grouped under:

Cone-rod dystrophy 2 (CORD2) is an inherited eye disorder that affects the rod and cone cells in the retina. These cells process light and allow people to see the accurate shape and color of objects.[1] Initial signs and symptoms of CORD2 usually occur in early childhood or late adolescence and include decreased sharpness of vision (visual acuity) and increased sensitivity to light (photophobia). Severity of symptoms and rate of disease progression may vary; however, most individuals experience impaired color vision, blind spots, loss of peripheral vision, and night blindness by adulthood.[1][2][3] CORD2 is caused by mutations in the CRX gene and is inherited in an autosomal dominant manner.[2] Though future treatment options such as gene therapy show promise in research studies; management currently focuses on slowing down the disease process, treating the complications and helping individuals to cope with the social and psychological impact of blindness.[4][5]
Last updated: 5/10/2016

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
1%-4% of people have these symptoms
Bone spicule pigmentation of the retina 0007737
Color vision defect
Abnormal color vision
Abnormality of color vision
[ more ]
0000551
Constriction of peripheral visual field
Limited peripheral vision
0001133
Macular hyperpigmentation 0011509
Metamorphopsia 0012508
Reduced visual acuity
Decreased clarity of vision
0007663
Retinal pigment epithelial atrophy 0007722
Percent of people who have these symptoms is not available through HPO
Abnormal electroretinogram 0000512
Autosomal dominant inheritance 0000006
Blindness 0000618
Central scotoma
Central blind spot
0000603
Chorioretinal atrophy 0000533
Cone/cone-rod dystrophy 0000548
Nyctalopia
Night blindness
Night-blindness
Poor night vision
[ more ]
0000662
Peripheral visual field loss
Loss of peripheral vision
0007994
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The U.S. National Institutes of Health, through the National Library of Medicine, developed ClinicalTrials.gov to provide patients, family members, and members of the public with current information on clinical research studies. There is a study titled Screening Study for the Evaluation and Diagnosis of Potential Research Participants which may be of interest to you.
  • ClinicalTrials.gov lists trials that are related to Cone-rod dystrophy 2. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease


These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Cone-rod dystrophy 2. This website is maintained by the National Library of Medicine.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Cone-rod dystrophy 2. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. cone-rod dystrophy. Genetics Home Reference. February 2016; https://ghr.nlm.nih.gov/condition/cone-rod-dystrophy.
  2. Victor A. McKusick. CONE-ROD DYSTROPHY 2; CORD2. In: Marla J. F. O'Neill. OMIM. 4/5/2013; http://www.omim.org/entry/120970.
  3. Cone-Rod Retinal Dystrophy. Retina International. http://www.retina-international.org/eye-conditions/retinal-degenerative-conditions/rare-conditions/#ConeRod. Accessed 5/10/2016.
  4. C. Hamel. Cone rod dystrophy. Orphanet. 2/2007; http://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=1843. Accessed 5/10/2016.
  5. Benjamin M. Nash, Dale C. Wright, John R. Grigg, Bruce Bennetts, Robyn V. Jamieson. Retinal dystrophies, genomic applications in diagnosis and prospects for therapy. Translational Pediatrics. April 2015; 4(2):139-163. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4729094/.