Cri du Chat disorder

1. Cri du Chat
Chromosome 5P Deletion Syndrome
Aravind Nair

2. Genetic Cause of Cri Du Chat
 Cri Du Chat is a genetic disorder caused by a deletion on the short arm of
Chromosome 5
 Various genes are deleted and each contributes towards the disorder
 TERT (Telomerase Reverse Transcriptase) – important during cell division because it helps
keep the tips of chromosomes (telomeres) intact

3. Inheritance
 There are two types of genetic disorders: hereditary and non-hereditary
 Hereditary disorders are those that are passed from parents to their offspring
 Non-hereditary disorders CANNOT be passed from parents to offspring and are
RANDOM occurrences
 Cri Du Chat is a NON-HEREDITARY disorder caused by a random deletion in
a section of Chromosome 5 and has nothing to do with the genetic
makeup of the parents
 However, it is important to note that in about 80% of the cases of Cri du
Chat, the deleted Chromosome 5 is paternal

4. Symptoms
 Small at birth
 Larynx does not develop correctly – causes the “cat-like cry”
 Small head
 Round Face
 Small Chin
 Wide Eyes
 Folds over skin/eyes
 Small bridge of nose
 Various internal problems
 Heart defects
 Muscular/skeletal problems
 Hearing/Sight problems
 Walking/Talking issues
 Behavioral problems (aggression, hyperactivity)
 Mental Retardation

5. Risk Factors
 Very Rare disorder: Affects estimated 1 in 20,000 to 50,000 births
 Found in all ethnic backgrounds
 Most common in females
 Most cases seem to occur in development of egg/sperm
 Most cases result when one parent carries a translocation of chromosome 5
 Translocation: Rearrangement of parts between the chromosomes that are not
members of the same pair
 Can be balanced: Fully functional which causes no physical differences

6. Treatments/Testing
 Symptoms may be individually treated, but there is no cure for the disorder
 If there are no major organ defects and critical medical conditions, life
expectancy is normal
 Speech/Language Therapy
 Doctors usually diagnose Cri du Chat by the “cat cry”
 New tests for diagnosing Cri du Chat in the womb
 Sample of tissue from outside the sac where the baby develops (chorionic villus
sampling [CVS])
 Sample of amniotic fluid that surrounds the baby (amniocentesis)

7. Sources
 http://learn.genetics.utah.edu/content/disorders/chromosomal/cdc/
 http://www.genome.gov/19517558
 http://www.healthline.com/health/cri-du-chat-syndrome#Causes2