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Though rare, cat eye syndrome can be life-changing. Whether you have the disorder or your child was born with it, you need to know what it entails.
What's in this Guide?
- What Is Cat Eye Syndrome?
- Is Cat Eye Syndrome Hereditary?
- Who Does Cat Eye Syndrome Typically Affect?
- What Causes Cat Eye Syndrome?
- Diagnosis of Cat Eye Syndrome
- Cat Eye Syndrome and Genetics
- Testing for Cat Eye Syndrome on a Pregnancy or Before a Pregnancy Is Achieved
- DNA Tests Currently Available for Cat Eye Syndrome Include:
- DNA Testing for Cat Eye Syndrome: Strengths and Limitations
- What Are the Chances That I Will Pass Cat Eye Syndrome Onto my Child?
- Cat Eye Syndrome Treatment Options
- The Prognosis for Cat Eye Syndrome
Disclaimer: Before You Read
It is important to know that your genes are not your destiny. There are various environmental and genetic factors working together to shape you. No matter your genetic makeup, maintain ideal blood pressure and glucose levels, avoid harmful alcohol intake, exercise regularly, get regular sleep. And for goodness sake, don't smoke.
Genetics is a quickly changing topic. Read More...
At YourDNA, we know it's important to you to learn everything you can about the disorder.
That's why we make it simple and present the facts in an easy-to-understand format that answers all the pertinent questions.
Cat eye syndrome (CES) is a very rare disorder, but it comes with its challenges.
The disorder can present in many ways, but there are typically three common symptoms that patients exhibit known as the classic triad.
Additionally, there is a correlation between cat eye syndrome and hearing loss, as well as vision problems.
However, there isn't much evidence to link cat eye syndrome and autism.
Parents of children with the disorder should learn all they can about it to help navigate through the proper treatments and care plans that will, in turn, give them the best chances of a normal life.
What Is Cat Eye Syndrome?
Cat eye syndrome (CES), also known as Schmid-Fraccaro syndrome, is a rare disorder that affects only 1 in every 50,000 to 150,000 people in the world 1.
There seem to be no solid hereditary ties, as most cases are spontaneous, but there have been reports of a family history of the disorder.
Most patients with cat eye syndrome are diagnosed young, typically in infancy through the toddler years.
It is not a fatal disorder, and many people who are diagnosed with it go on to live long, fulfilling lives.
The only exception to this is those who have severe symptoms such as a congenital heart defect which can, in some cases, lead to a shorter lifespan.
Symptoms of Cat Eye Syndrome
Cat eye syndrome presents differently in everyone who has it and the symptoms can range from mild to serious 2.
There are three common symptoms that affect between 80 and 99% of patients, including:
- Skin tags on the outer ears
- Pits in the outer ears
- Obstruction or absence of an anus
Other symptoms that may vary among those with the disorder include, but aren't limited to:
- Missing tissue in the colored part of either one or both eyes (iris coloboma)
- Intellectual disability, though no severe mental delays have been associated
- Congenital heart defects
- Abnormalities in the ribs
- Wide-set eyes
- Slanted openings between the lower and upper eyelids
- Defects in the kidneys or urinary tract, sometimes both
- Cleft palate
- Jaundice and other liver issues
- Hearing problems due to malformed ears
- Below average height
- Speech problems
There's no way to determine what type of symptoms a person with the disorder will exhibit, particularly if diagnosed in utero. The issues only become apparent after the child is born, and sometimes not even for years after that.
Is Cat Eye Syndrome Hereditary?
Cat eye syndrome is oftentimes the result of a spontaneous abnormality in chromosome 22 3. It's not typically passed down, however, there are rare cases of parents passing it down to their children 4.
This occurs when there's a balanced translocation that passes from the parent to the child.
Sometimes the parent has symptoms but they're so mild that they go undiagnosed or are diagnosed later in life.
Who Does Cat Eye Syndrome Typically Affect?
Cat eye syndrome does not discriminate between males and females, both genders have been diagnosed with the disorder.
Since it's caused by a duplication, it's present at birth and is often diagnosed in infants and babies.
What Causes Cat Eye Syndrome?
The main cause of cat eye syndrome is a mutation in chromosome 22. People with the disorder have an extra chromosome that's made up of duplicated parts.
Instead of having a long and short arm on this chromosome, people with this disorder often have triple or quadruple the parts in the extra chromosome.
Diagnosis of Cat Eye Syndrome
Diagnosing cat eye syndrome is often done based on the symptoms a patient exhibits.
In many cases, this is enough to ascertain whether a person has the disorder.
To confirm, doctors can do a few different tests.
How Do You Diagnose Cat Eye Syndrome?
Cat eye syndrome is diagnosed by a doctor and there are two types of testing that can help pinpoint the disorder: karyotype and FISH.
Both are laboratory tests, but they're carried out differently.
How Do Doctors Test for Cat Eye Syndrome?
Karyotype is when doctors and laboratory technicians produce a picture of the chromosomes a person has.
It can locate that third and problematic chromosome 22, confirming a diagnosis.
The other test is known as FISH, which uses a technique that locates DNA sequences on chromosomes.
Lab techs use a probe with a fluorescent molecule which binds to a specific sequence, giving the technicians a closer look.
In pregnant women, doctors can do cat eye syndrome prenatal tests through an amniocentesis to determine if the fetus has the disorder prior to their birth.
Cat Eye Syndrome and Genetics
Since cat eye syndrome isn't typically passed down, there's not a lot of concern when it comes to the genetics side of the disorder.
The abnormality is located on chromosome 22, and its presence is usually only detected when doctors notice the telltale symptoms.
Genetic Tests for Cat Eye Syndrome - Are They Available?
There are currently no at-home genetic tests that will identify CES.
However, anyone who's concerned that they might have a mild form of the disorder, or those looking for answers to their children's symptoms, can definitely ask for one to be done through their doctor's preferred laboratory.
The only testing available at this time is through a physician's order.
DNA testing to Spot or Detect Cat Eye Syndrome Early
If you're looking to spot or detect the disorder early, you can ask your child's pediatrician to run a DNA test to look for the additional chromosome.
However, most cases are detected in infancy and toddler-aged children, so the chances are that your doctor will likely want to test before you bring it up.
Testing for Cat Eye Syndrome on a Pregnancy or Before a Pregnancy Is Achieved
If you're currently pregnant or trying to conceive, you might be worried about the potential of passing on cat eye syndrome to your child if you have the disorder.
There are tests to detect the abnormal chromosome during pregnancy including amniocentesis and chorionic villus sampling (CVS).
Each of these requires collecting a fluid or tissue sample to test for it.
DNA Tests Currently Available for Cat Eye Syndrome Include:
There are two methods of DNA testing available for cat eye syndrome: karyotyping and the FISH method 5described above. These are available through a laboratory.
Where Can I Go for a Genetic Test?
The main place to visit to get a genetic test is through your doctor's office. Here, they can issue a prescription for you to have the testing done through a lab.
Of course, you can opt to have the testing done through a third-party, but you'll have to pay out of pocket as insurance companies typically only pay for those that come at a doctor's request.
DNA Testing for Cat Eye Syndrome: Strengths and Limitations
As with any form of testing, there are strengths and limitations to DNA testing for cat eye syndrome. The main strength is that a positive test result means you can begin treating the symptoms and you have a concrete diagnosis.
The main limitation is that if the results are positive, there's no way to ascertain how severe the symptoms will be through a DNA test.
Some people with the disorder have mild symptoms while others are more severe, sometimes even life-threatening.
What Are the Chances That I Will Pass Cat Eye Syndrome Onto my Child?
Though it's a genetic disorder, cat eye syndrome is rarely passed down from parent to child if the parent doesn't have it.
The risk increases, however, with parents who do have the disorder, though there are no known percentages.
If you have the disorder and you're uncertain of your odds of passing it down to your children, it's highly recommended that you speak with a genetic counselor.
Can Cat Eye Syndrome Be Prevented?
Currently, no. There are no known ways to prevent the disorder, though the current status of research on cat eye syndrome has scientists looking into the syndrome to learn more about it.
The more information they learn, the greater the potential for being able to implement preventative measures in the future.
Cat Eye Syndrome Treatment Options
Is Cat Eye Syndrome Treatable?
The disorder itself is not treatable, but the symptoms caused by CES usually are. It's not typically simple, though.
Because cat eye syndrome can affect different systems, patients often need a team of specialists who work together and may include:
- Optometrists or Ophthalmologists
- Digestive specialists
- Ear, Nose and Throat (ENT) doctors
Common treatments include, but are not limited to:
Patients with severe defects may require surgery. This is especially true for those who have congenital heart defects, as they'll sometimes need procedures to strengthen their heart and improve their overall quality of life.
Other surgical procedures may be needed to correct cleft palate issues, intestinal or anal issues and skeletal issues such as scoliosis.
There are different kinds of therapy designed to help those with CES. Hormone therapy, for example, helps people that have growth problems.
Physical and occupational therapies can benefit people with the disorder by helping them improve their overall motor skills.
Speech therapy is also required for some patients who have delayed speech or problems speaking clearly.
Some investigational therapies may be available for those who have the disorder.
Clinical trials are available throughout the country and can be found online.
Early intervention is often a sought-after service for young children with the disorder to help them succeed in school and in life.
Common services with early intervention include remedial education for those who have intellectual disabilities, social support and even vocational services as they age, to help them join the workforce seamlessly.
Counseling is beneficial for both parents and children with the disorder.
A genetic counselor can help with chromosomal studies that can determine whether the patient is a carrier of the CES chromosome or even if they have mosaicism, which is a cell with two genotypes.
The Prognosis for Cat Eye Syndrome
Currently, the prognosis for someone with cat eye syndrome is fairly positive with life expectancies similar to those of an average person, they just have to deal with the symptoms that come along with the disorder.
The symptoms do not get progressively worse, in most cases.
There are a few exceptions however, being those who have congenital heart defects or those with severe kidney or liver issues.
Does Cat Eye Syndrome Go Away?
No. Once a person has cat eye syndrome, they have it for life. In the future, researchers may be able to come up with a cure, but as of right now it's a lifelong affliction.
Is There a Cure for Cat Eye Syndrome?
There is no known cure for cat eye syndrome at this point. It's a chromosomal abnormality and as such, it's part of the person's makeup.
What Are Cat Eye Syndrome Care Options?
There are several different care options that a person with cat eye syndrome may undergo, though they do depend on the symptoms that the patient exhibits.
Many care plans include a form of therapy and intervention services to ensure that the patients succeed in school and in the workforce.
The outcomes depend on the severity of the symptoms and how well the person responds to treatment.
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- Cat Eye Syndrome.
National Organization for Rare Disorders assisted by Heather McDermid, PhD, Professor, Dept of Biological Sciences, University of Alberta, Edmonton, AB Canada.
- Chromosome 22.
National Library of Medicine. June 11, 2019.
- CAT EYE SYNDROME; CES.
"Online Mendelian Inheritance in Man : Cassandra L. Kniffin - updated : 2/13/2006
Creation Date: Victor A. McKusick : 6/4/1986 ".
- Genetics 101: cytogenetics and FISH.
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