What are the other Names for this Condition? (Also known as/Synonyms)

• CES (Cat Eye Syndrome)
• Chromosome 22, Inverted Duplication (22pter-22q11)
• Schmid-Fraccaro Syndrome

What is Cat Eye Syndrome? (Definition/Background Information)

• Cat Eye Syndrome (CES) is a rare congenital disorder involving chromosomal abnormalities of the 22nd chromosome. In this condition, the long and short arms of chromosome 22 are present 3-4 times rather than twice (like in normal cells)
• This leads to the signs and symptoms such as coloboma, downward slanting eyelid folds, and hearing impairment among others
• Currently, there are no known risk factors for Cat Eye Syndrome, and though CES is a genetic disorder, it is rarely passed down to a child from their parent(s)
• A healthcare provider can diagnose the condition through a physical examination at birth, or using an ultrasound when the fetus is in the womb
• Complications of Cat Eye Syndrome include vision, hearing, and cardiac defects. If left untreated, the condition can lead to a poor prognosis. If treated adequately through surgery and medication, the prognosis can be improved
• No known ways to prevent Cat Eye Syndrome are available at this time. Current medical research is trying to understand the cause of the condition, which can help scientists identify suitable preventative measures

Who gets Cat Eye Syndrome? (Age and Sex Distribution)

• Cat Eye Syndrome is a rare genetic disorder that occurs sporadically in individuals whose families have no history of the disorder
• Since it is a congenital disorder, it is present at birth; individuals can show symptoms throughout their life
• CES affects both males and females and shows no gender preference
• Individuals of all races and ethnic backgrounds may be affected

What are the Risk Factors for Cat Eye Syndrome? (Predisposing Factors)

• Currently, there are no  known risk factors for Cat Eye Syndrome

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Cat Eye Syndrome? (Etiology)

• Cat Eye Syndrome is a genetic disorder that is caused by an ‘inverted duplicated 22’. This means that each cell has extra genetic material from chromosome 22 that leads to the characteristic signs and symptoms
• It appears to arise sporadically, possibly because the parent's reproductive cells do not divide properly; the genetic abnormality occurs during the formation of either the sperm or the ovum
• Further research is needed to learn more about the genetic and chromosomal mechanisms responsible for Cat Eye Syndrome

What are the Signs and Symptoms of Cat Eye Syndrome?

The signs and symptoms of Cat Eye Syndrome can be highly variable. The eyes, ears, anal region, heart, and/or kidneys may be affected. Common signs and symptoms of CES include:

• Coloboma (hole in a structure of the eye) and a “keyhole” appearance of the iris
• Downward slanting eyelid folds and widely-spaced eyes
• Mild hearing impairment due to an absence of the external ear canal, and low-set or malformed auricles (outer portion of the ear)
• Small lower jaw
• Flat nasal bridge
• Anal opening may be small or absent
• Congenital heart defects
• Underdeveloped or absent kidneys
• Skeletal abnormalities

How is Cat Eye Syndrome Diagnosed?

Cat Eye Syndrome is diagnosed through the following tests and procedures:

• Physical examination and analysis of previous medical history
• Ultrasound scan of the affected region
• Analyzing specific markers through FISH analysis (specialized genetic technique)
• Amniocentesis: A sample of fluid is taken from the fluid surrounding the fetus and analyzed to look for the presence of an extra 22nd chromosome

Additionally, the healthcare providers can look for certain distinct features after birth, when diagnosing Cat Eye Syndrome:

• Heart malformations
• Kidney malformations
• Downward slanting eyelid folds
• Skin tags on the ears
• Absence of external ear canal

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Cat Eye Syndrome?

The complications of Cat Eye Syndrome may include:

• Vision defects due to coloboma
• Hearing defects
• Cardiac or heart abnormalities
• Kidney and gastrointestinal defects
• Mental health deficiencies
• Infection from surgical procedures

How is Cat Eye Syndrome Treated?

Presently, there is no cure for Cat Eye Syndrome; the treatment is based on the presenting signs and symptoms. It requires the combined effort of healthcare providers from various specialties. The treatment is dependent on the severity and type of symptoms each individual presents with.

The following measures may be considered towards treating CES:

• Physical therapy and/or surgery can be used to treat skeletal abnormalities associated with Cat Eye Syndrome
• Those with heart or kidney defects may need medication or surgery to alleviate the same
• Kidney transplantation for absent kidneys
• Structural abnormalities corrected through appropriate surgery
• Correcting any hearing issues

How can Cat Eye Syndrome be Prevented?

• Currently, there are no specific methods or guidelines to prevent Cat Eye Syndrome, since it is a genetic condition
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders such as Cat Eye Syndrome
• Regular medical screening at periodic intervals with tests, scans and physical examinations are mandatory

What is the Prognosis of Cat Eye Syndrome? (Outcomes/Resolutions)

• The prognosis for Cat Eye Syndrome depends on the severity of the signs and symptoms
• Infants who are severely affected by symptoms, such as heart and kidney malformations, and are unresponsive to treatment are known to die during infancy
• A majority of individuals with Cat Eye Syndrome have a normal life expectancy with appropriate treatment

Additional and Relevant Useful Information for Cat Eye Syndrome:

Please visit our Congenital & Genetic Disorders Health Center for more physician-approved health information:

http://www.dovemed.com/diseases-conditions/congenital-genetic-disorders/