Question

The cause of Cat-cry syndrome is due to
(a) Loss of a segment of X-chromosome
(b) Loss of a segment of 5’” chromosome
(c) Loss of a segment of Y-chromosome
(d) None of the above

Answer 1

Hint: Cri-du-chat syndrome is a rare genetic condition.
It is also known as cat's cry or 5P- syndrome, as it is caused by a deletion on the short arm of the 5th chromosome.

Complete answer:The chromosomal deletion generally occurs as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development.

People with cri du chat usually have no history of the condition in their family.
About only 10 percent of people with the disease inherit the chromosome with a deleted segment from an unaffected parent.
This condition of deletion in the short arm of chromosome 5 is an example of an unbalanced translocation, which is a chromosomal rearrangement with extra or even missing genetic material. Unbalanced translocations can typically cause birth defects and other health problems such as those seen in cri-du-chat syndrome. Interestingly, the variability of the clinical symptoms and developmental delays may be related to the size of the deletion of the 5p arm.

The symptoms of this rare disease include a high-pitched cat-like cry, mental retardation, distinctive facial features, small head size, widely-spaced eyes (hypertelorism), low birth weight, delayed development and weak muscle tone in infancy. The cat-like cry typically becomes less apparent with time. In most of the cases, people born with this disease have difficulty with language.

So, the correct answer is ‘Loss of a segment of 5’” chromosome’.

Note:No specific treatment is available for this syndrome.
Children born with this genetic condition will most likely require ongoing support from a team made up of the parents, therapists, and medical and educational professionals to help the child achieve maximum potential. However, with thorough educational intervention, as well as physical and language therapy, children with cri du chat syndrome can lead full and meaningful lives.