Cri-du-Chat

=CRI-DU-CHAT : CRY OF THE CAT=
 * BY SALLY & TRACEY**

Cri-du-Chat is a genetic disorder first described and named in 1963 by geneticist Jerome Lejeune. Cri-du-Chat means "cat's cry" in French. The disorder causes the baby to produce high-pitched and cat-like cry because of the structural abnormality and low muscle tone. Since 1963, many reports have been recorded of babies with abnormal cries. Studies have been carried out to grow the awareness of the disorder to many parents.
 * BEGINNING**

Cri-du-Chat is a genetic disorder results by the loss or deletion of the short arm of the chromosome 5. The five possibilities are as follows- 1. __Unbalanced Translocation__ - A translocation is when a piece of chromosome is separated from the chromosome and attaches to another chromosome. A translocation does not affect the individual if no material is lost or gained but if material is lost or gained, an unbalanced translocation has occurred. 2. __Ring Chromosome__- This genetic arrangement is when the each end of the chromosome breaks off and the ends are joined together to form a ring. Additional problems can occur depending on how much of material is lost from the long arm of the chromosome. 3. __Interstitial Deletion__- When a section from the short arm breaks off and the ends rejoin. The broken section may be deleted or attached to another chromosome. 4. __Inversion__- When a section of the chromosome breaks and flips or inverts before reattaching. Inversion could cause disorder because the code is reversed. 5. __Duplication or Partial Trisomy__- When a part of the short arm of chromosome 5 duplicates itself and attaches to the tip of the chromosome, disorder can occur because it results the code being misread.
 * [[image:http://www.pharmgkb.org/images/chromosomes/chr5.png width="157" height="495" align="left"]] WHAT CAUSES CRI-DU-CHAT?**

Any person can have Cri-du-Chat. It is one of the most common human deletion genetic disorder. The incidence varies from 1 in 20,000 to 1 in 50,000. The deletion in chromosome 5 is ~80% spontaneously occurred event. As far as we know, the disorder does not occur more in certain ethnic groups or regions. But the disorder is more common in girls than boys (ratio= 3 : 2).
 * CHANCES OF HAVING CRI-DU-CHAT**

The symptoms of Cri-du-Chat varies depending one the amount of material lost in the short arm of chromosome 5. The most common features are cat-like cry, mental retardation, growth failure, round face, and facial abnormalities (small head, small receding chin, widely spaced eyes, and folds of skin over the upper eyelid). No one knows how much the baby will be affected at birth. It is known that the location and size of the deletion is related to the degree of disability of the disorder. Cri-du-Chat causes more of physical characteristic abnormalities rather than mental abnormalities. The usual and common symptoms are shown in the paragraph above. Some features change as the child grows like the cat-like cry and the epicanthic folds (folds over the upper eyelid) may become less distinctive. But almost all children who have the syndrome have a problem like intellectual disability, delayed speech, short attention span, and slow development of muscle development. Some severe cases may show challenging acts such as obsession, repetition, and sometimes self-harming behaviors like head-banging, hitting, biting, or scratching themselves. Although the syndrome exists within the person for life, treatments have been developed to help lessen the symptoms. In childhood, many problems may follow such as minor skeletal problems, sometimes scoliosis, hernias, bowel abnormalities, and swallowing and sucking problems may follow. As the children grow up, additional problems may occur such as minor hearing impairments, frequent ear infections, commonly occurring turned eye, visual impairments, low/high muscle tone, saliva control problems, chronic constipation, and refusal to eat when suffering from illness (not interested in eating). After specific treatments, if the child is not critically affected, the child is able to persist a life as a normal child.
 * SYMPTOMS & EFFECTS**

There is no way of treating Cri-Du-Chat syndrome currently but in the future gene therapy (below picture) is a possibility for curing this genetic disorder and most of the medical problems caused by Cri-Du-Chat syndrome can be corrected through current medical treatments, operations, and therapies. Since most children with this disease experience both speech and language difficulties early intervention programs are often extremely helpful to the child especially since behavioral problems often result from instances when children experience a great deal of frustration from failure to communicate properly with others. In some cases sign language can also be helpful. Some early intervention programs such as speech therapy, occupational therapy, and physiotherapy are also useful. An important factor in dealing with Cri-Du-Chat syndrome is that in most cases it is not inherited because they result from a deleted chromosome that had occurred randomly during either the formation of reproductive cells or during early developmental stages. Only about 10% of people with Cri-Du-Chat syndrome inherited it from a parent who simply carried the disorder as a recessive trait.
 * TREATMENTS**
 * INHERITANCE**


 * DISCUSSION QUESTIONS**


 * 1**. What causes Cri-Du-Chat syndrome?


 * 2**. Can it be treated and if so, how? If not, are there ways to help the person?


 * 3**. How do you think this genetic disorder would affect a persons lifestyle?


 * WORKS CITED**


 * Created by Ivison, Bob. "What is cri-du-chat syndrome?" __Cri-du-chat Support Group of Australia Inc.__ Updated on 31 Dec. 2006. Date accessed -- 8 May 2007  ||
 * John Hopkins University. "Description." "Population Genetics." __Online Mendelian Inheritance in Man__. Updated on 1 May 2007. Date accessed -- 10 May 2007  ||
 * U.S. National Library of Medicine. "Cri-du-chat syndrome." __Genetics Home Reference.__ Updated on Jan. 2007. Date accessed -- 11 May 2007  ||