Question

The “cri-du-chat” syndrome is caused by change in chromosome structure involving
A. Deletion
B. Duplication
C. Inversion
D. Translocation

Answer 1

Hint:-Genetic disorders are caused by different types of mutations in a person's genome. Change in whole or in any part in DNA can lead to a genetic disorder. Some types of genetic mutations are deletion, duplication, inversion, and translocation.
These disorders can be inherited from parents and even can occur either randomly or due to some environmental exposure.

Complete step-by-step solution:-
Duplication is a type of mutation where one or more copies of a gene or region of a chromosome are produced.
Inversion mutation will occur when a part of a chromosome breaks off, flips around, and is again reattached.
In translocation, a part of a chromosome breaks and attaches to a different chromosome.
In this three mutation process, no loss of genetic material happens but in deletion mutation nucleotides from the genome is removed by mistake during the process of DNA replication. This mistake leads to the loss of genetic material.
“Cri-du-chat” is also caused by this deletion process due to a missing piece of genetic material on the ‘p’ arm of chromosome 5.
So the correct reason behind this genetic disorder is a deletion mutation. So, here option (A) is correct.

Note:-
This genetic disorder is present from birth which affects the growth and development of the patient. The symptoms of this disorder are cat-like cry, small head size, and a characteristic facial appearance.
People with this disability have an intellectual disability and they may have trouble breathing and feeding.
This mutation occurs very early in the development of an embryo and this syndrome usually did not inherit in families.