Cat Eye Syndrome. What Is It and Should You Worry?

What is Cat Eye Syndrome?

Cat eye syndrome (CES) is a rare congenital chromosomal disorder characterized by distinct facial features, organ abnormalities, and intellectual disability. It is caused by the presence of extra genetic material from chromosome 22 in some or all cells of the body.

The primary physical features of cat eye syndrome include coloboma, a keyhole-shaped defect in the colored part of the eye (iris); down-slanting eyelid folds (palpebral fissures); ear abnormalities; kidney malformations; heart defects; cleft lip and/or palate; and anal atresia. The degree of intellectual disability can range from mild to severe.

The name “cat eye syndrome” comes from the distinctive cat-eye shaped coloboma of the iris that affects more than half of individuals with this disorder. The coloboma results in a pupil defect that resembles the slit of a cat’s eye.

Common Physical Effects

Cat eye syndrome is associated with a wide range of physical abnormalities. Some of the most common include:

child with cat eye syndrome facial features

Facial abnormalities – Many individuals with cat eye syndrome have distinctive facial features such as widely spaced eyes, a flattened nose bridge, and downward slanting eyelid folds (Source).

Heart defects – Congenital heart defects occur in around 80% of people with cat eye syndrome. Some of the most common defects include atrial septal defect, ventricular septal defect, and tetralogy of Fallot (Source).

Kidney problems – Kidney abnormalities, such as missing, small, or abnormally formed kidneys, occur in 30-50% of individuals. This can lead to chronic kidney disease or renal failure (Source).

Intellectual disability – Most individuals with cat eye syndrome have some degree of intellectual disability, with IQ scores ranging from 50-70. Learning disabilities are also common (Source).

Developmental Effects

Children with cat eye syndrome frequently experience developmental delays and learning disabilities. Speech delays are very common, with most children beginning to speak later than their peers. On average, first words emerge around age 2 and sentences around age 4, compared to 12-18 months for typically developing children. Language impairments often persist into adulthood (Source).

In addition to speech and language deficits, cat eye syndrome is associated with intellectual disability or learning disabilities in 50-60% of cases. Average IQ scores range from 50-70, though there is significant individual variation. Academic difficulties are common even among those with normal intelligence. Areas of challenge include reading, writing, math, visual-spatial skills, and memory (Source).

child receiving speech therapy

Behavioral issues are also more prevalent, including autism, ADHD, obsessive compulsive tendencies, and oppositional behaviors. Children may require extra support and therapy to develop social skills and emotional regulation (Source). Early intervention services can help maximize development and quality of life.

Is Cat Eye Syndrome Harmful?

The severity of symptoms associated with cat eye syndrome can vary greatly from person to person. While some symptoms may be noticeable at birth, others may not be identified until later in childhood.

According to the National Organization for Rare Disorders (, the most common features of cat eye syndrome include characteristic eye abnormalities, mild intellectual disability, and heart defects present at birth. However, the symptoms range from barely noticeable to life-threatening.

Although there is no cure for cat eye syndrome, many of the effects can be treated or managed. For example, heart defects may require surgery, antibiotics may be prescribed for recurrent infections, and various therapies can help with developmental delays. Proper early intervention is key.

The life expectancy for individuals with cat eye syndrome depends greatly on the severity of symptoms. According to one study cited in OMIM (, most patients reach adulthood, with a subset having relatively mild symptoms and a normal lifespan. However, severe congenital heart defects and kidney malformations can negatively impact prognosis in some cases.

While cat eye syndrome should not be taken lightly, the outlook can be significantly improved through proper management of symptoms and a multidisciplinary approach to care.

Treatment and Management

There is currently no cure for cat eye syndrome since it is caused by a permanent genetic change. However, many of the symptoms associated with the condition can be treated and managed to improve quality of life.

Early intervention is important for developmental delays that may occur. Speech therapy, physical therapy, and occupational therapy can help strengthen areas of weakness and ensure children reach their full potential. Tracking development at regular checkups allows providers to notice any emerging issues and begin therapies as soon as possible.

child with therapist during developmental assessment

Ongoing medical care is also crucial. Cardiac issues may require surgery or medication. Skeletal problems can be corrected with braces or surgery. Hearing and vision should be monitored regularly. Providers can also offer guidance on diet and exercise programs tailored to the individual.

While cat eye syndrome itself cannot be cured, its symptoms can be treated and managed to ensure the best possible health and development. With early intervention and dedicated medical care, many of the potential effects of the condition can be greatly improved or corrected (Source).

Causes and Inheritance

Cat eye syndrome is caused by the presence of an extra chromosome 22 in a person’s cells ( In most cases, cat eye syndrome occurs randomly for unknown reasons during the formation of reproductive cells (eggs and sperm) in a parent. In this scenario, there is a very low chance for recurrence in future pregnancies.

In approximately 10-15% of cases, cat eye syndrome can be inherited from a parent with the disorder ( This occurs when the extra chromosome is present in some of the parent’s egg or sperm cells. If one of these reproductive cells contributes to the genetic makeup of a child, the child will have cat eye syndrome as well. The risk of passing it on is still relatively low, around 15% or less.

Overall, cat eye syndrome is considered a random sporadic genetic disorder, and the risk of recurrence is generally low. However, genetic counseling and testing can provide more accurate risk assessment for families affected by inherited cases.


Cat eye syndrome is typically diagnosed through a combination of physical exams to look for characteristic symptoms, along with genetic testing to confirm the diagnosis. Some key aspects of diagnosis include:

Physical Exam: A physician will conduct a detailed physical exam, looking closely at the eyes, ears, anal region, heart, and kidneys for abnormalities that are common in cat eye syndrome. Features like downward slanting eyelid folds and small skin tags around the eyes are suggestive of cat eye syndrome.

Genetic Testing: The definitive way to diagnose cat eye syndrome is through genetic testing, usually chromosome analysis. This involves examining the chromosomes from a blood sample under a microscope. In cat eye syndrome, there is an extra (“marker”) chromosome 22 which confirms the diagnosis (1).

Prenatal Screening: Cat eye syndrome can sometimes be detected prenatally through amniocentesis or chorionic villus sampling. These procedures allow examination of the fetus’ chromosomes for abnormalities. Ultrasound may also reveal certain physical birth defects associated with cat eye syndrome, prompting further genetic testing (2).

Living with Cat Eye Syndrome

Living with cat eye syndrome can present various challenges, but being proactive and utilizing available resources and support can help significantly. Some tips for living with cat eye syndrome include:

Joining support groups can provide great benefit. Connecting with other families impacted by cat eye syndrome allows sharing of experiences and practical advice. Two organizations that offer support networks are the National Organization for Rare Disorders (NORD) and the Unique Rare Chromosome Disorder Support Group.

Seeking out disability services can be crucial. Many children with cat eye syndrome qualify for early intervention and special education services. Vocational rehabilitation programs and disability benefits may also be available for adults. Services can assist with therapy, education plans, and employment.

Developing good coping strategies helps manage the emotional aspects. Seeing a counselor, practitioner, or therapist allows discussion of concerns and fears. Maintaining a strong support system of family and friends also aids coping. Focusing on strengths and abilities, not just limitations, promotes a positive outlook.

Outlook and Prognosis

The outlook for individuals with cat eye syndrome can be quite variable depending on the severity of symptoms and associated abnormalities. However, with early intervention and proper management, many people with cat eye syndrome can live fairly normal lives.

Some of the factors that influence prognosis include the degree of intellectual disability, presence of congenital heart defects, kidney abnormalities, and other malformations. Milder cases may have minimal impact on physical and mental development. More severe cases can result in significant cognitive impairment and physical disabilities.

With proper medical care and educational support, many children with cat eye syndrome can attend mainstream schools, develop friendships, and live independently as adults. Early intervention with speech therapy, physical therapy and special education services are important. Medications may help manage symptoms associated with learning disabilities or mental health issues.

Life expectancy is often normal, unless there are serious complications like complex congenital heart defects. Some degree of intellectual disability is common, but intelligence quotients can range from below average to normal. While mild developmental delays are typical, many adults with cat eye syndrome can complete vocational training, hold jobs, and live productive lives with some degree of independence.

group of young adults with disabilities

While cat eye syndrome is a lifelong condition, many of the associated medical problems can be managed or treated. With appropriate support services and a nurturing environment, children and adults with cat eye syndrome have a largely positive long-term outlook.

The Takeaway

In summary, Cat Eye Syndrome is a rare genetic disorder caused by the partial triplication of chromosome 22. It can result in a wide array of physical effects like facial abnormalities, heart defects, kidney problems, and musculoskeletal anomalies. Intellectual disability and developmental delays are also common.

While these symptoms can negatively impact quality of life, early intervention and proper management can help those with Cat Eye Syndrome live relatively normal lives. Access to medical care, education services, speech and physical therapy, and psychosocial support are key, especially in childhood. With proper treatment, many of those affected are able to attend school, develop relationships, and live independently as adults.

In the end, Cat Eye Syndrome requires extra care and attention, but it is a manageable condition. With early diagnosis and support, individuals with this disorder can overcome challenges and thrive.

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