Cri du chat syndrome

Cri du chat syndrome is caused by a deletion of the end of the short (p) arm of chromosome 5. This chromosomal change is written as 5p-. The size of the deletion varies among affected individuals but studies suggest that larger deletions tend to result in more severe intellectual disability and developmental delay than smaller deletions.

The signs and symptoms of cri du chat syndrome are probably related to the loss of multiple genes on the short arm of chromosome 5. Researchers believe that the loss of a specific gene, CTNND2, is associated with severe intellectual disability in some people with this condition. They are working to determine how the loss of other genes in this region contributes to the characteristic features of cri du chat syndrome.

Most cases of cri du chat syndrome are not inherited. The deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Most affected individuals do not have a history of the disorder in their family.

About 10 percent of people with cri du chat syndrome inherit the chromosome abnormality from an unaffected parent. In these cases, the parent carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Balanced translocations usually do not cause any health problems; however, they can become unbalanced as they are passed to the next generation. Children who inherit an unbalanced translocation can have a chromosomal rearrangement with extra or missing genetic material. Individuals with cri du chat syndrome who inherit an unbalanced translocation are missing genetic material from the short arm of chromosome 5. This results in the intellectual disability and other health problems characteristic of the disorder.

While not hallmark clinical features of this syndrome, skeletal abnormalities still have been observed in affected children with some frequency. These anomalies may include: abnormal side-to-side curvature of the spine (scoliosis); flat foot, clubfeet; syndactyly (webbing of the fingers and toes); and abnormal bending or curving of the pinkies inward toward the fourth finger (clinodactyly). Inguinal hernia and diastasis recti have been reported as well.

Most individuals with cri du chat syndrome have a normal life expectancy. A small number of children with this condition are born with serious organ defects and other life-threatening medical problems. These children may have a worse prognosis. In these cases, it is best to obtain information about prognosis from the affected person's physician.

General information about prognosis for cri du chat syndrome can be accessed through Medscape Reference.

While there is no specific treatment available for cri du chat syndrome, early intervention is recommended in the areas of physical therapy (achieving physical and motor milestones such as sitting and standing up), communication (speech therapy, sign language instruction), behavioral modification (for hyperactivity, short attention span, aggression), and learning (special education). Because symptoms may vary from individual to individual, we recommend discussing these options with a health care professional to develop a personalized plan for therapy.

Nguyen JM et al., 5p deletions: Current knowledge and future directions. Am J Med Genet C Semin Med Genet. 2015 Sep;169(3):224-38.

Boultwood J et al., Advances in the 5q- syndrome. Blood. 2010 Dec 23;116(26):5803-11.

Pituch KA et al., Educational Priorities for Children with Cri-Du-Chat Syndrome. J Dev Phys Disabil. 2010 Feb;22(1):65-81.

Rodríguez-Caballero A et al., Cri du chat syndrome: a critical review. Med Oral Patol Oral Cir Bucal. 2010 May 1;15(3):e473-8.

Cornish K, Bramble D. Cri du chat syndrome: genotype-phenotype correlations and recommendations for clinical management. Dev Med Child Neurol. 2002 Jul;44(7):494-7.