“Cri du chat” syndrome: some novelties for an “old” syndrome

Key words: “Cri du chat” syndrome, Deletion, Chromosome 5, Neurological development

“Cri du chat” syndrome (CdC, OMIM 123450) is classified among the rare diseases. It was described for the first time in 1963 and it is due to a deletion in the short arm of chromosome 5 (in about 90% of cases as a result of a sporadic “de novo” deletion). The span and the position of the deletion correlate with the phenotype. To date, at least 2 genes, which seem to be involved in neurological development (semaphorine F and !- catenin), have been mapped in the critical region. At birth, CdC children show low birthweight, microcephalia, high-pitched cry, epicanthus, downslanted palpebral fissures, round face with full cheeks, low set ears, and flat nasal bridge. Diagnosis can be easy if all the clinical signs are present, but delayed in children with atypical features. Clinical features change with age: coarse face, microcrania, prominent supraorbital ridges, malocclusion, flat feet, and scoliosis. Intellectual disability is influenced by genetic and environmental factors and a continuous and personalized rehabilitation programme is needed to prevent regression. Behavioural problems (hyperactivity, tantrum, self harm, and repetitive movements) are often present; reduced sensitivity to pain could be a possible explanation. In the last 30 years data from about 300 patients have been collected in Italy, thanks to the cooperation with ABC (Associazione Bambini Cri du Chat). The present work reports auxologic and developmental charts and tries to increase knowledge in order to suggest the best follow up and rehabilitation programmes.