Cri-du-chat Syndrome: Cause Explained

Cri-du-chat syndrome is a rare genetic disorder that affects development. The name 'Cri-du-chat' is French for 'cat's cry' because infants with this syndrome often emit a high-pitched cry that sounds like a meowing cat, which is one of its characteristic features.

This specific chromosomal aberration occurs when a piece of a chromosome is lost. In the case of Cri-du-chat syndrome, the issue arises from a deletion on the short arm (denoted as 'p') of chromosome 5. This means a small segment of the genetic material on chromosome 5 is missing.

Let's look at why the other options are not the cause:

• Duplication: This involves having an extra copy of a chromosome segment, rather than a missing piece.
• Inversion: This is when a segment of a chromosome breaks off, flips around, and reattaches to the same chromosome.
• Translocation: This occurs when a piece of one chromosome breaks off and attaches to another chromosome.

Therefore, the primary cause of Cri-du-chat syndrome is a deletion of genetic material from chromosome 5p.