What is Cri du Chat Syndrome?
Cri du Chat Syndrome arises from the absence of a particular portion of Chromosome 5. The absence of genetic material is called a deletion. Children born with this deletion have a characteristic mewing cry that is thought to be caused by abnormal development of the larynx (the organ containing the vocal chords). For this reason, the disorder is called Cri du Chat (or Cat’s Cry) Syndrome. In reference to the deletion and the area where it occurs, the disorder is also called 5p- (5 p minus) Syndrome. Children with this syndrome have physical abnormalities, language and motor skill difficulties, and varying degrees of intellectual disabilities. Cri du Chat Syndrome is a very rare disorder.
How is it manifested?
- high-pitched cry (identified as a cat-like cry)
- low birth weight
- poor muscle tone (hypotonia)
- microcephaly (small head size)
- micrognathis (small jaw)
- hypertelorism (wide spaced eyes)
- round face
- epicanthal folds (small skin folds on the inner corners of the eyes)
- low set ears
- feeding difficulties
- delay in walking
- language difficulties
- intellectual disabilities
- organ defects
Who is affected?
The estimated prevalence is about 1 in 20, 000-50,000 newborns. Most cases of Cri du Chat Syndrome are not inherited. The deletion mostly occurs at random during the formation of reproductive cells (eggs or sperm) or in early fetal development. However, about 10 per cent of people affected inherit a chromosome abnormality/rearrangement called a balanced translocation from an unaffected parent. Balanced translocations usually do not cause any health problems. When a child inherits the unbalanced translocation, however, there is a possibility of a chromosal rearrangement with extra or missing genetic material. Individuals with Cri du Chat Syndrome are missing genetic material from the short arm of Chromosome 5.
How is it diagnosed or detected?
During infancy, a diagnosis of Cri du Chat Syndrome is strongly suspected if the characteristic cat-like cry is heard. If a child has this unusual cry, or other features seen in Cri du Chat Syndrome, chromosome testing should be performed. Chromosome analysis provides a definitive diagnosis of Cri du Chat Syndrome and can be performed from a blood test. Chromosome analysis, also called “karyotyping,” involves staining the chromosomes and examining them under a microscope. In some cases the deletion of material from Chromosome 5 can be easily seen. In other cases, further testing must be performed. Fluorescence In-Situ Hybridization (FISH) is a special technique that detects very small deletions. The majority of the deletions that cause Cri du Chat Syndrome can be identified using the FISH technique.
5P- SOCIETY – www.fivepminus.org
The 5p- Society (five p minus), a not-for-profit corporation, is the parent support group for families having a child with 5p- Syndrome, also known as Cat Cry Syndrome or Cri du Chat Syndrome. Their mission is to encourage and facilitate communication among families having a child with 5p- Syndrome and to spread awareness and education of the syndrome to these families and their service providers.
ALLIANCE OF GENETIC SUPPORT GROUPS – www.geneticalliance.org
Genetic Alliance is an international coalition comprised of more than 600 advocacy, research and healthcare organizations that represent millions of individuals with genetic conditions and their interests. As a broad-based coalition of key stakeholders, they leverage the voices of millions of individuals living with genetic conditions.
CANADIAN ORGANIZATION FOR RARE DISORDERS (CORD) – www.raredisorders.ca
CORD is Canada’s national network for organizations representing all those with rare disorders. CORD provides a strong common voice to advocate for a health policy and a healthcare system that works for those with rare disorders. CORD works with governments, researchers, clinicians and industry to promote research, diagnosis, treatment and services for all rare disorders in Canada.
CORD will link other families and individuals with the same rare disorder(s) through a positive and productive networking system. Together they can exchange ideas on how to plan their daily lives, what they can expect to encounter, and offer emotional support so that they can lead productive lives.
The content contained in this document is for general information purposes. It is not intended to diagnose or treat a child.