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

Cat eye syndrome

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Other Names:
Schmid-Fraccaro syndrome; CES; Chromosome 22 partial tetrasomy; Schmid-Fraccaro syndrome; CES; Chromosome 22 partial tetrasomy; INV DUP(22)(Q11) See More
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Cat eye syndrome is a chromosome abnormality that affects many different parts of the body. The signs and symptoms of the condition vary widely but may include abnormalities of the eyes, ears, anal region, heart and/or kidney.[1][2] In people affected by cat eye syndrome, each cell has at least one small extra (duplicate) chromosome made up of genetic material from chromosome 22. This extra genetic material leads to the characteristic signs and symptoms of the condition.[3] Most cases of cat eye syndrome occur sporadically in people with no family history of the condition. Treatment is symptomatic.[2]
Last updated: 4/13/2015
The signs and symptoms of cat eye syndrome vary, but may include:[1][2][4]
  • Iris coloboma
  • Anal atresia (opening to the anus is missing)
  • Skin tags or pits in front of the ears
  • Unusually shaped ears
  • Conductive hearing loss
  • Hypertelorism (widely spaced eyes)
  • Downward slanting palpebral fissures (outside corners of the eyes point downward)
  • Strabismus
  • Cleft lip and/or palate
  • Congenital heart defects
  • Urinary tract problems
  • Skeletal abnormalities
  • Developmental delay
  • Mild to moderate intellectual disability
Last updated: 4/11/2015

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.

Showing of 32 |
Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Anal atresia
Absent anus
0002023
Preauricular pit
Pit in front of the ear
0004467
Preauricular skin tag 0000384
30%-79% of people have these symptoms
Abnormal localization of kidney
Abnormal localisation of kidneys
0100542
Abnormality of cardiovascular system morphology 0030680
Abnormality of the ribs
Rib abnormalities
0000772
Chorioretinal coloboma
Birth defect that causes a hole in the innermost layer at the back of the eye
0000567
Downslanted palpebral fissures
Downward slanting of the opening between the eyelids
0000494
Hip dysplasia 0001385
Hydronephrosis 0000126
Hypertelorism
Wide-set eyes
Widely spaced eyes
[ more ] 		0000316
Intellectual disability, mild
Mental retardation, borderline-mild
Mild and nonprogressive mental retardation
Mild mental retardation
[ more ] 		0001256
Intrauterine growth retardation
Prenatal growth deficiency
Prenatal growth retardation
[ more ] 		0001511
Iris coloboma
Cat eye
0000612
Muscular hypotonia
Low or weak muscle tone
0001252
Renal hypoplasia/aplasia
Absent/small kidney
Absent/underdeveloped kidney
[ more ] 		0008678
Short stature
Decreased body height
Small stature
[ more ] 		0004322
5%-29% of people have these symptoms
Abnormality of the genital system
Genital abnormalities
Genital abnormality
Genital anomalies
Genital defects
[ more ] 		0000078
Hearing impairment
Deafness
Hearing defect
[ more ] 		0000365
Microphthalmia
Abnormally small eyeball
0000568
Percent of people who have these symptoms is not available through HPO
Abnormal heart morphology
Abnormality of the heart
Abnormally shaped heart
Heart defect
[ more ] 		0001627
Absent radius
Missing outer large bone of forearm
0003974
Autosomal dominant inheritance 0000006
Biliary atresia 0005912
Cleft palate
Cleft roof of mouth
0000175
Growth abnormality
Abnormal growth
Growth issue
[ more ] 		0001507
Intestinal malrotation 0002566
Low-set ears
Low set ears
Lowset ears
[ more ] 		0000369
Micrognathia
Little lower jaw
Small jaw
Small lower jaw
[ more ] 		0000347
Renal agenesis
Absent kidney
Missing kidney
[ more ] 		0000104
Stenosis of the external auditory canal
Narrowing of passageway from outer ear to middle ear
0000402
Total anomalous pulmonary venous return 0005160
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Last updated: 7/1/2020
Cat eye syndrome is most often caused by a chromosome abnormality called an inverted duplicated 22. In people with this condition, each cell has at least one small extra (duplicate) chromosome made up of genetic material from chromosome 22. This extra genetic material leads to the characteristic signs and symptoms of cat eye syndrome.[3]
Last updated: 12/15/2016
Most cases of cat eye syndrome are not inherited. The condition generally occurs sporadically as a random event during the formation of the egg or sperm. In this case, a person would have no family history of the condition but could pass it on to children.[1][2]

Rarely, cat eye syndrome is passed down from parent to child. Some of these cases are the result of a balanced translocation in one of the parents. Carriers of a balanced translocation generally do not have any unusual symptoms or health problems; however, they have an increased risk of having children with a chromosome abnormality. In other cases, the parent may have a small extra (duplicate) chromosome made up of genetic material from chromosome 22 in some (mosaicism) or all of their cells. Because the symptoms and severity can vary between family members, the parent may not have any obvious symptoms or may only be mildly affected.[1][2]
Last updated: 4/11/2015
A diagnosis of cat eye syndrome is often suspected based on the presence of characteristic signs and symptoms. Genetic testing can then be ordered to confirm the diagnosis. This testing may include:[2][5]
  • Karyotype - a karyotype is a laboratory test that produces an image of a person's chromosomes.
  • FISH - a laboratory technique that is used to detect and locate a specific DNA sequence on a chromosome. During FISH, a chromosome is exposed to a small DNA sequence called a probe that has a fluorescent molecule attached to it. The probe sequence binds to its corresponding sequence on the chromosome.

In some cases, cat eye syndrome can be diagnosed before birth. If suspicious features are observed on prenatal ultrasound, follow up testing such as an amniocentesis or chorionic villus sampling may be ordered to further investigate a diagnosis.[2][5]
Last updated: 4/12/2015

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.
Because cat eye syndrome affects many different systems of the body, medical management is often provided by a team of doctors and other healthcare professionals. Treatment for this condition varies based on the signs and symptoms present in each person. For example, congenital heart defects; anal atresia; cleft lip and/or palate; and certain skeletal abnormalities may require surgery. Children with delayed motor milestones (i.e. walking) may be referred for physical therapy or occupational therapy. Special education services are often necessary for children with intellectual disability.[1][2][4]
Last updated: 4/12/2015
The long-term outlook (prognosis) for people with cat eye syndrome varies from person to person and largely depends on the severity of the condition and the associated signs and symptoms, specially when there are heart or kidney problems. Some babies who are very severely affected die during infancy; however, most people with cat eye syndrome do not have a shortened life expectancy.[5]
Last updated: 4/6/2018
Around 1 out of 50,000 to one of out 150,000 people in the general population are thought to have cat eye syndrome.[1]
Last updated: 12/15/2016

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

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnosis includes other chromosomal disorders with overlapping phenotypes such as CHARGE syndrome and VACTERL/VATER association (see these terms).
Visit the Orphanet disease page for more information.

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 Cat eye syndrome. 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 Cat eye syndrome. 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. Cat-eye syndrome. Orphanet. January 2016; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=195.
  2. Cat Eye Syndrome. NORD. 2017; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/1085/viewAbstract.
  3. Chromosome 22. Genetics Home Reference. September 2016; http://ghr.nlm.nih.gov/chromosome/22.
  4. Rosa RF, Mombach R, Zen PR, Graziadio C, Paskulin GA. Clinical characteristics of a sample of patients with cat eye syndrome. Rev Assoc Med Bras. July-August 2010; 56(4):462-465.
  5. Cat Eye Syndrome. OMIM. 2009; http://www.ncbi.nlm.nih.gov/omim/115470. Accessed 12/15/2016.