Question

Identify the chromosomal disorder based on the given statements:
i. There is only a partial deletion of chromosome
ii. The deletion is seen in the 5th chromosome
iii. Infants with this disorder have a high pitched cry

• A. Cri-du-chat syndrome
• B. Down’s syndrome
• C. Turner’s syndrome
• D. Edwards syndrome

Answer 1

The correct option is A Cri-du-chat syndrome

A normal human being has 46 chromosomes in all the somatic cells. Any deviation from this number in terms of loss or addition of chromosomes leads to chromosomal disorders.

Even deletion, duplication or inversion of a part of chromosome also leads to chromosomal disorders.

The partial deletion of the 5th chromosome results in Cri-du-chat syndrome. Also known as cat’s cry, since infants with this disorder have a high pitched cry that sounds like a cat crying.

Down’s syndrome is a chromosomal disorder which is caused due to nondisjunction of the ${21}^{st}$ chromosome resulting in the presence of an extra ${21}^{st}$ chromosome.

Edward’s syndrome is a chromosomal disorder which is caused due to nondisjunction of the ${18}^{th}$ chromosome resulting in the presence of an extra ${18}^{th}$ chromosome.

Turner’s syndrome is characterised by the absence of an X chromosome in females.