Facts About Cri-Du-Chat Syndrome

•The geneticist Jerome Lejeune identified cri-du-chat syndrome in 1963.
•He also discovered the genetic abnormality that causes Down syndrome.
•Cri-du-chat is one of the most common syndromes caused by a chromosomal deletion.
•Between 1 in 20,000 and 1 in 50,000 babies.
•In 80 percent of the cases, the chromosome carrying the deletion comes from the father's sperm rather than the mother's egg.
• When deletions occur during the formation of an egg or sperm, it is caused by unequal recombination during meiosis.
•When unequal recombination occurs at this location on chromosome 5, it causes cri-du-chat syndrome.