(See also Overview of Chromosome Disorders Overview of Chromosome and Gene Disorders Chromosomes are structures within cells that contain a person's genes. A gene is a segment of deoxyribonucleic acid (DNA) and contains the code for a specific protein that functions in one or... read more .)
Cri-du-chat syndrome is a rare syndrome in which part of chromosome 5 is missing. The size of the missing part varies, and people who have larger deletions are often more severely affected.
Symptoms of cri-du-chat syndrome often include a characteristic high-pitched, mewing cry that sounds like a kitten crying. This cry may be heard immediately after birth, lasts several weeks, and then disappears. However, not all affected newborns have this distinct cry. An infant with this syndrome may have a low birth weight and a small head with many abnormal features, including a round face, small jaw, wide nose, widely separated eyes, crossed eyes (strabismus Strabismus Strabismus is an intermittent or constant misalignment of an eye so that its line of vision is not pointed at the same object as the other eye. If untreated, strabismus can cause amblyopia ... read more ), and abnormally shaped ears set low in the head. Often the infant seems limp. Webbed fingers and toes (syndactyly Finger and Toe Defects The fingers and toes may be abnormally formed, incompletely formed, or missing at birth. Birth defects of the fingers and toes can occur while a baby is developing in the womb. For example,... read more ) and heart defects are common. There are significant limitations in mental and physical development. Many children with cri du chat syndrome survive to adulthood but have substantial disabilities.