Cri du Chat Syndrome

1. Risk factors

1.1. risk of recurrence in a patient’s younger sibling is low unless one parent is a carrier of a chromosomal rearrangement involving 5p.

1.2. risk of having another child with a chromosomal imbalance involving 5p could be 15–25% if a parental translocation is present

2. Diagnostic tests

2.1. type of genetic test called FISH analysis may be needed to reveal the deletion

2.1.1. Fluorescence in situ hybridization (FISH) is a test that “maps” the genetic material in a person's cells

2.2. generally diagnosed in the hospital at birth

2.3. missing portion (deletion) of the short arm of chromosome 5 may be seen on a chromosome analysis

3. Common findings

3.1. high-pitched cat-like cry

3.2. delayed development

3.3. widely-spaced eyes (hypertelorism)

3.4. small head size (microcephaly)

3.5. distinctive facial features

3.6. low birth weight and weak muscle tone (hypotonia) in infancy

3.7. mental retardation

4. Genetic details and pathophysiologic etiology

4.1. also known as 5p- syndrome and cat cry syndrome

4.2. cause of this rare chromosomal deletion is unknown

4.3. the key genes associated with the phenotypes seen in Cri du Chat syndrome have not yet been identified

4.4. rare genetic condition that is caused by the deletion (a missing piece) of genetic material on the small arm (the p arm) of chromosome 5.

4.4.1. de novo unbalanced translocations in 5% of patients

4.4.2. de novo deletions of 5p in 90% of patients

4.4.3. missegregation of familial translocations in 5% of patients

5. Causative factors

5.1. typically have no history of the condition in their family

5.2. chromosomal deletion usually occurs as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development

5.3. About 10 percent of people with cri du chat syndrome inherit the chromosome with a deleted segment from an unaffected parent

6. Treatments

6.1. No specific treatment is available for this syndrome

6.2. Ongoing support from a team

6.2.1. parents, therapists, and medical and educational professionals to help the child achieve his or her maximum potential