Cri-du-Chat

Genetic Disorder Project

What is Cri-du-Chat?

Cri-du-Chat is a rare genetic disorder where a varied portion of the short arm of chromosome 5 is deleted or missing. This disorder is in the chromosomal abnormalities category of genetic disorders.

Discovered

This disorder was first described in medical literature in 1963 by doctor Jerome Lejeune. Cri du chat in French means "cry of the cat", so he named it that due to the cat-like cry that is a symptom of the disorder.

Symptoms

These are some symptoms that this disorder causes, some are more likely than others but they are all possible.

-small at birth

-respiratory problems

-larynx doesn't develop right causing the signature cat-like cry

-microcephaly

-unusually round face

-small chin

-widely set eyes

-folds of skin over their eyes

-small bridge of the nose

-small number have heart defects,muscular or skeletal problems, or poor muscle tone

-as they grow usually have a difficult time walking and talking

-behavioral problems like hyperactivity or aggression

-severe intellectual disability

Life expectancy is normal as long as there are no major organ defects or critical medical conditions.

Inheritance

Most cases appear to happen spontaneously for no known reasons early in the embryonic development. The number of people who get this disorder ranges from 1-15,000 to 50,000 live births. The gene for this disorder is located on chromosome 5. This disorder affects females more often than males. 10-15 percent of cases can result from a balanced translocation with chromosome 5p and another chromosome. Translocations happen when areas of certain chromosomes break off and are rearranged causing shifted genetic material and an altered set of chromosomes. Translocations can be transmitted by a carrier of a balanced translocation. A balanced translocation is usually harmless to the carrier but may be associated with an increased risk of abnormal chromosomal development in the carriers offspring.

Diagnosis

There is a possible way to test before the baby is born by taking a tiny sample of tissue from outside the sac where the baby develops, or testing a sample of the amniotic fluid that surrounds the baby. Doctors normally identify the syndrome after the baby is born by the infants cat-like cry, microcephaly(smallness of the head), poor muscle tone and mental retardation. Doctors can however have a difficult time diagnosing CDC after age two because it usually becomes less noticeable as the baby gets older.

Treatment

There isn't any way to prevent this disorder but there are ways to treat it depending on specific symptoms in each individual. Most children start having therapy before their first birthday. Some therapies include:

-special remedial education

-physical therapy

-speech therapy

Some children may require efforts of a team of specialists to plan an affected child's treatment, sometimes they may even need surgery to treat their certain symptoms such as:

-congenital heart defects

-strabisums (abnormal alignment of the eyes)

-scoliosis

-clubfoot (foot is twisted out of shape or position)

-cleft palate

-cleft lip

Organizations

One large organization for Cri-du-Chat is the National Organization for Rare Diseases, or NORD. This organization gives you information on the rare disease you are looking for and you can even donate and raise awareness. Some support groups are 5P Minus Society (www.fivepmius.org/) and Cri du Chat Syndrome Support Group (http://criduchat.org.uk/).