Definition of Cri du chat syndrome:

Cri du chat syndrome is a group of symptoms that result from missing a piece of chromosome number 5. The syndromeâ ' s name is based on the infantâ ' s cry, which is high-pitched and sounds like a cat.

Causes, incidence, and risk factors:

Cri du chat syndrome is rare. It occurs when a piece of information on chromosome 5 is missing. It is likely that multiple genes on chromosome 5 are deleted. One deleted gene, called TERT (telomerase reverse transcriptase) is involved in control of cell growth, and may play a role in how some of the features of this syndrome develop.

Most cases are believed occur during the development of an egg or sperm. A minority of cases result from one parent carrying a rearrangement of chromosome 5 called a translocation.

Between 1 in 20,000 - 50,000 babies are affected. This disease may account for up to 1% of individuals with severe mental retardation.