Question

Cri-du-chat syndrome in humans is caused by the

• A. fertilisation of an XX egg by a normal Y- bearing sperm
• B. loss of half of the short arm of hromosome5
• C. loss of half of the long aim of chromosome 5
• D. trisomy of 21st chromosome

Answer 1

Answer: (B)

Cri-du-chat (cat cry) syndrome in human is caused by the deletion of short arm of chromosome $5$.
The affected new born cries like mewing of cat.
The trisomy of $21^{\text {st }}$ chromosome causes Down's svndrome (mongolism).