Cri du chat (patient information)

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 * Assistant Editor-in-Chief: Ethan Leeman

Overview
Cri du chat syndrome is a group of symptoms that result from missing a piece of chromosome number 5. The syndrome’s name is based on the infant’s cry, which is high-pitched and sounds like a cat.

Cri-du-chat syndrome occurs in an estimated 1 in 20,000 to 50,000 newborns. This condition is found in people of all ethnic backgrounds. This syndrome may account for up to 1% of individuals with severe mental retardation.

What are the symptoms of Cri du chat?

 * Cry that is high-pitched and sounds like a cat
 * Downward slant to the eyes
 * Low birth weight and slow growth
 * Low-set or abnormally shaped ears
 * Mental retardation
 * Partial webbing or fusing of fingers or toes
 * Single line in the palm of the hand (simian crease)
 * Skin tags just in front of the ear
 * Slow or incomplete development of motor skills
 * Small head (microcephaly)
 * Small jaw (micrognathia)
 * Wide-set eyes

What are the causes of Cri du chat?
Cri du chat syndrome is rare. It happens when genetic information on chromosome 5 is missing. One missing piece, called TERT (telomerase reverse transcriptase) is involved in control of cell growth, and may play a role in how some of the features of this syndrome develop.

Most cases are believed to occur during the development of the egg or sperm. A minority of cases result from one parent carrying a rearrangement of chromosome 5 called a translocation and passing this on to the baby.

Most cases of cri-du-chat syndrome are not inherited. The deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Affected people typically have no history of the disorder in their family.

About 10 percent of people with cri-du-chat syndrome inherit the chromosome abnormality from an unaffected parent. In these cases, the parent carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Balanced translocations usually do not cause any health problems; however, they can become unbalanced as they are passed to the next generation. Children who inherit an unbalanced translocation can have a chromosomal rearrangement with extra or missing genetic material. Individuals with cri-du-chat syndrome who inherit an unbalanced translocation are missing genetic material from the short arm of chromosome 5, which results in the intellectual disability and health problems characteristic of this disorder.

How to know you have cri du chat?
In addition to symptoms listed above, the physical examination may show:
 * Inguinal hernia
 * Diastasis recti (separated abdominal muscles)
 * Low muscle tone
 * Epicanthal folds, an extra fold of skin over the inner corner of the eye
 * Incompletely or abnormally folded external ears

Genetic tests can show a missing part of chromosome 5. Skull x-ray may reveal an abnormal angle to the base of the skull.

When to seek urgent medical care
This is a diagnosis that is generally made in the hospital at birth. Your health care provider will discuss your baby's signs and symptoms with you. When you leave the hospital, it's important to maintain regular contact with your health care provider and other caregivers. Genetic counseling and testing is recommended for all persons with a family history of this syndrome.

Treatment options
No specific treatment is available for this syndrome. The mental retardation must be addressed, and counseling is recommended for the parents.

Parents of a child with this syndrome should have genetic counseling and a karyotype test to determine if one parent has a rearrangement of chromosome 5.

Where to find medical care for Cri du chat?
Directions to Hospitals Treating Cri du chat

Prevention of Cri du chat
There is no known prevention. Couples with a family history of this syndrome who wish to become pregnant may consider genetic counseling.

What to expect (Outlook/Prognosis)?
What can be expected varies, but mental retardation is usual. Half of children with Cri du chat syndrome learn sufficient verbal skills to communicate. The cat-like cry becomes less apparent over time.