Question

Cri du chat syndrome in humans is caused by the :

• A. Fertilization of an XX egg by a normal Y - bearing sperm
• B. Loss of half of the short arm of chromosome 5
• C. Loss of half of the long arm of chromosome 5
• D. Trisomy of 21st chromosome

Answer 1

The correct option is B Loss of half of the short arm of chromosome 5

Cri-du-chat (cat's cry) syndrome, also known as 5p- (5p minus) syndrome, is a chromosomal condition that results when the short arm of chromosome 5 is missing.
Infants with the syndrome produce a high-pitched cry that sounds like a cat. The larynx develops abnormally due to the chromosome deletion, which affects the sound of the child’s cry. The syndrome is more noticeable as the child ages but becomes difficult to diagnose past age 2.