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Disease Profile

Coats disease

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)

Retinal telangiectasis; Leber miliary aneurysm


Congenital and Genetic Diseases; Eye diseases; Nervous System Diseases


Coats disease is an eye disorder characterized by abnormal development of the blood vessels in the retina (retinal telangiectasia). Most people begin showing symptoms in childhood. Early signs and symptoms vary but may include vision loss, "crossed eyes" (strabismus), and a white mass in the pupil behind the lens of the eye (leukocoria). Over time, Coats disease may also lead to retinal detachment, glaucoma, and clouding of the lens of the eye (cataracts). In most cases, only one eye is affected. Coats disease is not inherited and the underlying cause is not known. It has been theorized that some cases may be due to somatic mutations (acquired, not inherited) in the NDP gene. Treatment depends on the symptoms present and may include cryotherapy and laser photocoagulation (alone or in combination), steroids for inflammation, and/or surgery for retinal detachment.[1][2]


The signs and symptoms of Coats disease typically begin at an early age (between ages 6 and 8).[3] The disorder may occur at any age, but the majority of people with Coats disease are diagnosed in the first two decades of life. Some people may have few or no symptoms, while others are very severely affected.[1] The condition is almost always progressive (symptoms get worse over time), although alternating periods of sudden worsening with periods of no apparent progression are common.[3]

Early signs and symptoms may include loss of vision, misalignment of the eyes (strabismus), and/or the development of a white mass in the pupil behind the lens of the eye (leukocoria).[1] As the disease progresses, affected people may develop glaucomacataracts, reddish discoloration in the iris (rubeosis iridis or neovascular glaucoma), shrinking of the affected eyeball (phthisis bulbi), and/or swelling and irritation of the middle layer of the eye (uveitis). Over time, Coats disease may cause detachment of the retina and substantial loss of vision.[1][3]

When Coats disease occurs with additional abnormalities that affect the brain, bones, gastrointestinal system, and other parts of the body, it is called Coats plus syndrome.[4]

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:
80%-99% of people have these symptoms
Abnormal retinal vascular morphology
Abnormality of retina blood vessels
Squint eyes

[ more ]

30%-79% of people have these symptoms
Abnormal macular morphology
Retinal detachment
Detached retina
5%-29% of people have these symptoms
Abnormal anterior chamber morphology
Aplasia/Hypoplasia of the iris
Absent/small iris
Absent/underdeveloped iris

[ more ]

Clouding of the lens of the eye
Cloudy lens

[ more ]

Percent of people who have these symptoms is not available through HPO
Exudative retinal detachment
Retinal telangiectasia
Somatic mutation


The cause of Coats disease is not currently known. It has been theorized that somatic mutations (acquired, not inherited) in the NDP gene may lead to isolated cases of Coats disease. However, this has not been proven.[1]

Coats disease has been reported as one feature of several genetic syndromes.[3] In these cases, the underlying cause of each syndrome may be responsible for Coats disease. When Coats disease occurs with additional abnormalities that affect the brain, bones, gastrointestinal system, and other parts of the body, it is called Coats plus syndrome and is caused by mutations in the CTC1 gene.[4]


A diagnosis of Coats disease is often suspected based on the presence of signs and symptoms, and findings on a thorough eye examination. Specialized tests to confirm the diagnosis and rule out other conditions may include retinal fluorescein angiography, diagnostic echography, and in some cases, a CT scan of the orbits, and/or MRI.[1][2]


Treatment for Coats disease depends on the severity in each person.[1] The following treatments (used alone or in combination) may be tried:

More advanced disease with extensive retinal detachment may also require surgical interventions such as vitrectomy, scleral buckling to correct a detached retina, and external drainage of fluids.[5]


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

    Social Networking Websites

    • RareConnect has an online community for patients and families with this condition so they can connect with others and share their experiences living with a rare disease. The project is a joint collaboration between EURORDIS (European Rare Disease Organisation) and NORD (National Organization for Rare Disorders).

      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

        • 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

          • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
          • 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 Coats disease. Click on the link to view a sample search on this topic.


            1. Coats Disease. NORD. 2017; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/837/viewFullReport.
            2. Hubbard B, Laird P. Coats disease. Orphanet. July, 2013; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=190.
            3. Del Longo A. Coats disease. Orphanet Encyclopedia. September 2004; https://www.orpha.net/data/patho/Pro/en/Coats-FRenPro1645.pdf.
            4. Coats Plus Syndrome. Genetics Home Reference. April 2014; https://ghr.nlm.nih.gov/condition/coats-plus-syndrome.
            5. Cebeci Z, Bayraktar S, Yilmaz YC, Tuncer S, Kir N. Evaluation of Follow-Up and Treatment Results in Coats' Disease. Turk J Ophthalmol. October, 2016; 46(5):226-231. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5200835/.
            6. Shields JA, Shields CL, Honavar SG, Demirci H, Cater J. Classification and management of Coats disease: the 2000 Proctor Lecture. American Journal of Ophthalmology. May 2001; 131(5):572-583.

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