Cri Du Chat Syndrome: Causes, Symptoms, Treatment

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Cri-Du-Chat (Cat's Cry) Syndrome

Jerome Lejeune, a geneticist, identified Cri du chat syndrome in the year 1963; he is also the person who discovered the genetic abnormality which causes Down syndrome. The syndrome's name is French for 'cry of the cat' and refers to children with the disorder's distinctive cry. The cry is caused by abnormal development of a child's larynx when they have the syndrome, which commonly becomes noticeable as they become older, which can make it more difficult for a doctor to diagnose Cri du chat past the age of two.

Main Digest

Cri Du Chat Syndrome is caused by a deletion on the short arm of chromosome five. Several genes are missing due to the deletion, and each can contribute to the symptoms the child experiences. One of the deleted genes known to be involved is referred to as 'TERT,' or telomerase reverse transcriptase,' which is important during cell division because it assists in keeping the tips of chromosomes intact. Additional names Cri du chat are called 'Chromosome 5p deletion syndrome,' '5p minus syndrome,' and 'Cat cry syndrome.'

The U.S. Social Security Administration (SSA) has included Cri du Chat Syndrome as a Compassionate Allowance to expedite a disability claim.

Causes

Cri du chat is one of the most common syndromes caused by chromosomal deletion, affecting between one in twenty-thousand and one in fifty-thousand children. Eighty percent of children affected by the syndrome experience chromosome deletion from their father's sperm rather than their mother's egg. When these deletions in the child's chromosomes occur during sperm or egg formation, it is caused by unequal recombination during meiosis. Recombination usually happens between pairs of chromosomes during meiosis while lined up at the metaphase plate. If the chromosomes do not line up as they should, or if the chromosome breaks are not repaired appropriately, the structure of the chromosome may be altered. When unequal recombination happens at this location on chromosome five - the result is Cri du chat syndrome.

Deletions are caused by a break in the person's DNA molecule that makes up a chromosome. In most instances, the chromosome breaks happen while the sperm or egg cell, also referred to as the 'male or female gamete, is still developing. The child will develop Cri du chat syndrome when the gamete becomes fertilized. The parent themselves, however, does not have the break in any other cells in their body; they do not have the syndrome themselves. The break is usually so rare that it is unlikely to happen again, should the same parent have another child. It is possible, though, for a child to inherit a broken chromosome from a parent who also had Cri du chat syndrome.

Symptoms of Cri Du Chat Syndrome

Children born with Cri du chat syndrome are commonly small at birth. They may also experience respiratory difficulties and a larynx that does not develop as it should, leading to the characteristic cat-like cry associated with the syndrome. People with Cri du chat syndrome present with very distinctive features, such as a small head or, 'microcephaly,' a small chin, a round face, a small bridge of the nose, and folds of skin over their eyes.

People with the syndrome can also experience several problems inside their bodies. Some children with Cri du chat syndrome have skeletal problems, heart defects, poor muscle tone, or hearing and vision difficulties. As children with the syndrome grow, they often experience difficulties with talking or walking and can have behavioral difficulties such as hyperactivity or aggression, as well as severe mental retardation. If a child with Cri du chat syndrome does not experience defects with major organs or other critical medical conditions, their life expectancy is average. The population of people with Cri du Chat syndrome might account for approximately one percent of persons with severe mental retardation.

The symptoms of Cri du chat syndrome can include:

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

Diagnosing

Most of the time, a doctor can identify Cri du chat syndrome by an infant's cat-like cry, which is distinctive. Additional signs include microcephaly, mental retardation, and poor muscle tone. Chromosomal testing is another means of testing for the syndrome while a child is still in the mother's womb. An expert can either test a small sample of tissue from outside the sac where the child develops, referred to as 'chorionic villus sampling or CVS,' or they may test a sample of amniotic fluid known as 'amniocentesis.'

A physical examination of the child can also reveal different things. The child may experience an inguinal hernia, separated abdominal muscles, 'diastasis recti,' incompletely or abnormally folded ears, or an extra fold of skin over the inner corner of their eye, referred to as 'epicanthal folds.' A skull X-ray can also show an abnormal angle at the base of the child's skull.

Treatment

Medical science has not created a form of treatment for Cri du chat syndrome at this time. Children with the syndrome may, however, pursue therapy with the goals of improving their motor and language skills, as well as assisting them with development. Mental retardation can also be addressed through a variety of means. There is no known way to prevent Cri du chat syndrome. People with a family history of the syndrome who wish to become pregnant might consider genetic counseling.

Author Credentials:

Thomas C. Weiss is a researcher and editor for Disabled World. Thomas attended college and university courses earning a Masters, Bachelors and two Associate degrees, as well as pursing Disability Studies. As a Nursing Assistant Thomas has assisted people from a variety of racial, religious, gender, class, and age groups by providing care for people with all forms of disabilities from Multiple Sclerosis to Parkinson's; para and quadriplegia to Spina Bifida.

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