Rare Rheumatology News

Disease Profile

Cone-rod dystrophy 2

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

CORD2; Cone-rod retinal dystrophy 2; CRD2;


Eye diseases


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]


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.

Medical Terms Other Names
Learn More:
1%-4% of people have these symptoms
Bone spicule pigmentation of the retina
Color vision defect
Abnormal color vision
Abnormality of color vision

[ more ]

Constriction of peripheral visual field
Limited peripheral vision
Macular hyperpigmentation
Reduced visual acuity
Decreased clarity of vision
Retinal pigment epithelial atrophy
Percent of people who have these symptoms is not available through HPO
Abnormal electroretinogram
Autosomal dominant inheritance
Central scotoma
Central blind spot
Chorioretinal atrophy
Cone/cone-rod dystrophy
Night blindness
Poor night vision

[ more ]

Peripheral visual field loss
Loss of peripheral vision


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.


    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

      Organizations Providing General Support

        Learn more

        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.


            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; https://www.omim.org/entry/120970.
            3. Cone-Rod Retinal Dystrophy. Retina International. https://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; https://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. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4729094/.