This article needs additional citations for. Unsourced material may be challenged and removed. It was first described by in 1963. The condition affects an estimated 1 in 50,000 live births across all ethnicities and is more common in females by a 4:3 ratio. Cri du chat, or Cri-du-chat Facial features of a patient with Cri du chat syndrome at the age of 8 months A , 2 years B , 4 years C and 9 years D The syndrome gets its name from the characteristic cry of affected infants, which is similar to that of a kitten, due to problems with the and. About one third of children lose the cry by age of 2 years. Other common findings include , a round face with full cheeks, , down-slanting eyelids , , flat , down-turned mouth, , , and cardiac defects e. It has also been observed that people with the condition have difficulties communicating. Less frequently encountered findings include , and , , , , , , , , rare renal malformations e. The syndrome may also include various , including transverse flexion creases, distal axial triradius, increased whorls and arches on digits and a. Late childhood and adolescence findings include significant intellectual disability, , coarsening of facial features, prominent , deep-set eyes, hypoplastic nasal bridge, severe and. Affected females reach puberty, develop and menstruate at the usual time. The genital tract is usually normal in females, except for a report of a. In males, testes are often small, but is thought to be normal. Exceptionally, some with Cri du chat are very high-functioning and do not seem very different from developmentally typical individuals, with mostly the exception of mild learning difficulties, and do not have speech difficulties, although they may have milder facial features and a high-pitched voice due to their condition. The remaining 10-15% are due to unequal segregation of a parental where the 5p monosomy is often accompanied by a trisomic portion of the genome. These individuals may have more severe disease than those with isolated monosomy of 5p. A recent study suggests this may not be the case where a of chromosome 4q is involved. Most cases involve total loss of the most distant 10-20% of the material on the short arm. Fewer than 10% of cases have other rare cytogenetic aberrations e. The deleted chromosome 5 is paternal in origin in about 80% of de novo cases. Loss of a small region in band 5p15. The results suggest that 2 noncontiguous critical regions contain genes involved in this condition's cause. Two genes in these regions, SEMA5A and CTNND2 , are potentially involved in cerebral development. The deletion of the hTERT gene localized in 5p15. Diagnosis is based on the distinctive cry and accompanying physical problems. These common symptoms are quite easily observed in infants. Affected children are typically diagnosed by a doctor at birth. Prenatally the deletion of the cri du chat related region in the of can be detected from or with BACs-on-Beads technology. G-banded karyotype of a carrier is also useful. Children may be treated by speech, physical and occupational therapists. Heart abnormalities often require surgical correction. NORD National Organization for Rare Disorders. Case Reports in Genetics. Retrieved 25 August 2017. Orphanet Journal of Rare Diseases.