Supporting people with Cri du Chat Syndrome and their families


CdCS is usually diagnosed within the first few days of birth, though for some babies this takes longer. The syndrome is diagnosed by looking at the combination of symptoms, physical examination by a specialist, and finally by genetic testing.

Diagnosis can sometimes happen before birth with a genetic test (via an amniocentesis or CVS test), though there are few known signs that would indicate that a pre-birth test is needed.

Experts will look for symptoms such as:

  • Cry that is unusually high-pitched and sounds like a cat
  • Low birth weight and slow growth
  • Intellectual disability
  • Slow or incomplete development of motor skills
  • Small head (microcephaly)
  • Small jaw (micrognathia)
  • Wide-set eyes
  • Downward slant to the eyes
  • An extra fold of skin over the inner corner of the eye (Epicanthal folds)
  • Low-set or abnormally shaped ears
  • Skin tags just in front of the ear
  • Partial webbing or fusing of fingers or toes
  • Single line in the palm of the hand

When doing a physical examination, they may find:

  • Low muscle tone
  • Inguinal hernia
  • Separation of the muscles in the belly area (Diastasis recti)
  • Problems with the folding of the outer ears

Genetic Testing

A full genetic test (using a small blood sample) is the only way to be 100% sure, and a specialist will normally do this if they suspect that the syndrome is present. This is normally carried out through your local NHS genetics service.

Parents & family

There is a 10-15% chance that the syndrome is inherited from a parent. If you are a parent, you should be offered a genetic test to see if you are a carrier. This means that you have the missing piece of the fifth chromosome, but not in the right place; a translocation.

If neither parent is a carrier, then there is no increased risk to the immediate family, close relations, or future children.

If one parent a carrier, then there is a high risk of future children having the syndrome, and it may be worth their siblings and any existing children having genetic tests as well.

You can get leaflets on counselling and advice for family members from Genetic Alliance