Question

`Cri-du chat' syndrome is an autosomal genetic disorder due to :
1. Non-disjunction
2. Deletion
3. Mutation
4. Duplication

Answer 1

Correct Answer - Option 2 : Deletion

Explanation:

• Cri du chat syndrome: It is a rare autosomal chromosome disorder. It occurs due to the deletion in the short arm of the 5^th chromosome.
• It is derived from the French term "cat-cry" or "call of the cat" which refers to the cat-like crying characteristic of the affected children.
• The children affected by this disease suffer from problems with the larynx and nervous system.
• Symptoms include:

1. Low weight at the time of birth
2. Small jaw & head
3. Speech disability
4. widely spaced eyes
5. Problem during swallowing of food

• Mutation: It is defined as the change of gene sequence in the organism’s genome by deletion, addition, or translocation such that it alters the genetic message carried by that gene.
• Non-disjunction: It refers to the phenomena when the homologous chromosomes fail to separate during the cell division. It results in the abnormal chromosome number in the daughter cells (Aneuploidy). It may occur during three stages Meiosis I, Meiosis II, or Mitosis.
• Duplication: It is a type of chromosomal aberration. It is the occurrence of a chromosomal segment twice on a chromosome