Cri du Chat syndrome

Also known as: Chromosome 5 Short Arm Deletion; Deletion 5p- syndrome

Background

Cri du Chat syndrome is a caused by a deletion of a small piece of chromosome 5 and is estimated to occur in around 1 in 15,000 to 50,000 babies born. Infants with this condition often have a high-pitched cry that sounds like a cat. The condition is characterised by delayed development and learning disability, small head size, low birth weight and low muscle tone in infancy. Affected individuals also have distinctive facial features and some children with Cri du Chat syndrome are born with a heart defect (see entry Heart Defects).

Credits

Medical text written in July 2001 by Professor K Cornish, Canada Research Chair in Neuropsychology and Education, McGill University, Montreal, Canada and Dr D Bramble, Consultant Child and Adolescent Psychiatrist, Nottingham University, Nottingham, UK. Last updated April 2020 by Dr M Suri, Consultant Clinical Geneticist, Nottingham City Hospital, Nottingham, UK.

Although great care has been taken in the compilation and preparation of all entries to ensure accuracy, we cannot accept responsibility for any errors or omissions. Any medical information is provided is for education/information purposes and is not designed to replace medical advice by a qualified medical professional.

What are the symptoms?

There is a lot of variation in symptoms amongst individuals. Common symptoms include:

  • hallmark ‘cat-like’ cry, which tends to disappear with time
  • low birth weight and faltering growth
  • feeding difficulties
  • microcephaly (small head size)
  • hypotonia (reduced muscle tone)
  • certain facial characteristics:
  • round face
  • hypertelorism (widely spaced eyes)
  • down ward slant to the eyes
  • medial epicanthic folds (a fold of skin over the inner aspect of the eyes)
  • squint
  • low-set ears
  • broad nasal bridge
  • short philtrum (the area between the nose and upper lip)
  • macrostomia (unusually wide mouth)
  • down-turned angles of the mouth
  • micrognathia (a small jaw)   
  • short neck
  • partial webbing or fusion of fingers or toes
  • a single transverse crease over the palm of the hands
  • slow or incomplete development of developmental skills
  • learning disability
  • heart defects

Children with Cri du Chat syndrome are prone to developing recurrent upper respiratory tract infections and middle ear infections and may have dental problems. They are also at increased risk of developing scoliosis (spinal curvature). They can expect to live a normal life-span, though individuals will display differing degrees of reliance on others for daily support.

What are the causes?

Cri du Chat syndrome is caused by a deletion of the end of the short (p) arm of chromosome 5. The size of the deletion can vary between affected individuals.  The signs and symptoms of the syndrome are probably related to the loss of multiple genes.  It is believed that loss of the 5p15.2 region (band 15.2 of the p arm) is responsible for most of the features of Cri du Chat syndrome although loss of the 5p15.3 region is likely responsible for the characteristic ‘cat-like’ cry.   

How is it diagnosed?

Cri du Chat syndrome will be suspected if common clinical features are present. In the past this condition was diagnosed by a combination of standard chromosome analysis with fluorescent in situ hybridisation (FISH) analysis.  Now, most instances of this condition will be diagnosed by a chromosomal microarray test, which will detect the missing part of chromosome 5p and will also be able to size the deletion and identify it gene content.

How is it treated?

There is no cure for Cri du Chat syndrome. Regular follow-up by a Paediatrician or Community Paediatrician is recommended to monitor nutrition and growth, developmental progress, progress with learning, hearing, eyesight including squint and the spine.  The routine schedule of childhood immunisation is advised to reduce likelihood of infections. Early physiotherapy, speech and language therapy and occupational therapy are recommended to improve learning, coordination and movement. Corrective surgery may be required for heart defects and progressive scoliosis.

Inheritance patterns and prenatal diagnosis

Inheritance patterns
Most cases of Cri du Chat syndrome are not inherited. The deletion occurs as a new event (sporadically) in these individuals. About 10% of people with Cri du Chat syndrome inherit the chromosome abnormality from an unaffected parent. In these cases, the parent carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. However, this can result in the birth of a baby with an unbalanced chromosome pattern, including the chromosome change responsible for Cri du Chat syndrome. Families affected by the condition should seek genetic advice.

Prenatal diagnosis
Chorionic villus sampling at 11 to 12 weeks and amniocentesis at 15 to 16 weeks are available to test for the chromosome 5 deletion in affected families.

Is there support?

Cri du Chat Syndrome Support Group

Email: office@criduchat.org.uk
Website: criduchat.org.uk

The Group is a Registered Charity in England and Wales No. 1044942. It provides information and support to anyone affected by Cri Du Chat Syndrome in the UK or abroad. The Group offers an annual family weekend for families, carers and professionals. It also has a Clinical Advisory Group which is a multi-disciplinary group of professionals who provide up to date information and a prompt advisory service on clinical matters.

Group details last updated April 2020.

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