Cri-du-chat (French for "cat's cry") is a
congenital syndrome in
humans caused by the loss of
genetic material on the short arm of the 5th
chromosome. The syndrome, which was first described by a
researcher named Lejeune in 1963, gets its name because
infants and young
children with the
disorder make a high-pitched,
cat-like crying noise.
Children with the syndrome tend to have round faces, low-set ears, small jaws and abnormally small heads (microcephaly). They also exhibit a lack of normal muscle tone and they usually have moderate-to-severe mental and psychomotor retardation. They may have other physical problems such as scoliosis and deformities of their internal organs. About 1 in 50,000 babies are born with the syndrome; it is one of the most common syndromes caused by genetic deletions.
Many people with cri-du-chat have periods of aggressive, destructive behavior and self-mutilation, and they typically have trouble with speech. However, with early childhood educational intervention and physical therapy, children with milder forms of the syndrome can attend school and experience a full life.