Cri-du-chat syndrome, also known as chromosome 5p deletion syndrome, is caused by a deletion on the short arm of chromosome 5. It is characterized by a cat-like cry in affected infants due to problems with larynx development. Other symptoms include small size, mental retardation, small head and jaw, distinctive facial features and limb abnormalities. While there is no cure, treatment focuses on managing symptoms through physical and speech therapy. The condition occurs in approximately 1 in 20,000 to 50,000 live births.

1. cri-du-chat syndrome
Balbeer Singh
Biosciences (V)
Szabist

2. Cri du Chat: The Cat’s Cry

3. Cri du chat syndrome, also known
as chromosome 5p deletion syndrome

4. Its name is a French term
cat-cry or call of the cat
referring to the characteristic
cat-like cry of affected children.

5. The characteristic cry of
affected infants, which is similar
to that of a meowing kitten, due
to problems with the larynx.
The larynx is not developed
properly.

6. SYMPTOMS
Normal brain size
TOP: Normal ear position/size
BOTTOM: Ear position/size with cri-du-chat
Microcephaly Low-set ears
Brain size with cri-
du-chat

7. SYMPTOMS
 Babies with cri-du-chat are usually small at
birth, and may have respiratory problems.
 Often, the larynx doesn’t develop correctly,
which causes the signature catlike cry.
 Mental retardation
 Small head (microcephaly).
Small jaw (micrognathia).

8. Downward slant of the eyes.
Wide-set eyes.
Abnormally shaped/positioned ears.
Webbed fingers or toes.
Single line in the palm of the hand (simian
crease).
Hanging skin in front of the ears.
Slow or incomplete development of
basic skills.

9. Cause
• Cri-du-chat is caused by a deletion on the
short arm of chromosome 5p – the length of
the deletion may vary.
• Multiple genes are missing as a result of this
deletion, and each may contribute to the
symptoms of the disorder.

10. • One of the deleted genes known to be
involved is HTERT (human telomerase reverse
transcriptase).
• HTERT helps to keep the information in DNA
functioning properly.
• If HTERT is damaged, mental illnesses such as
cri-du-chat occur.

11. Inheritance of Cri-du-Chat
 The deletion that causes cri-du-
chat syndrome is caused by a
dominant trait.
 CTNND2 is an important gene
that is lost when a portion of the
5 pair chromosome is deleted.
 CTNND2 gene usually makes the
delta catenin protein. This protein
works in the nervous system and
helps with cell movement.
 The loss of CTNND2 may cause
severe brain damage in some
patients.
CTNND2 gene under a
microscope.
Delta
catenin
protein.

12. Diagnosis
 Doctors most often identify cri-du-chat by looking at
the patient’s symptoms.
 Another method of diagnosing cri-du-chat
syndrome takes place while the baby is still in its
mother's womb.
 Doctors can either test a tiny sample of tissue from
outside the sac where the baby develops, or they
can test a sample of the amniotic fluid – the
protective liquid in the womb from which a baby
gets nourishment.

13. Treatment
• There is no specific treatment
available for this disorder so medical
care is focused on the symptoms.
Physical therapy is recommended to
strengthen the muscles. To increase
communication skills, a speech
therapist can help the child learn to
use sign language.

14. Statistics
 Approximately 90% of cases of cri-du-chat
syndrome result from a randomly-occurring
deletion.
 The remaining 10% occurs purely by inheritance.
 Cri-du-chat syndrome occurs in an estimated 1 in
20,000 to 50,000 newborns.
 Cri-du-chat can occur in all races and in both
genders, although there is a slight female
predominance. The male to female ratio is 3:4.
 Approximately 30% of infants with cri-du-chat have
heart defects.
 About 1/3 of infants lose the catlike cry at age 2.

15. Interesting Facts
 The geneticist Jerome Lejeune identified cri-du-chat
syndrome in 1963. He also discovered the genetic
abnormality that causes Down syndrome.
 In 80% of cri-du-chat cases, the chromosome
carrying the deletion comes from the father’s sperm
rather than the mother’s eggs.
 If pairs of chromosomes don’t line up correctly
during metaphase in meiosis, the structure of a
chromosome can be changed. When this happens
with chromosome 5, it causes cri-du-chat.
 Cri-du-chat is the most common syndrome caused
by deletion.

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