PEDBASE.org - The Pediatric Database - Detailed information of CRI DU CHAT SYNDROME

CRI DU CHAT SYNDROME

DEFINITION:

A chromosomal disorder characterized by a partial deletion of the short arm of chromosome 5 resulting in a cat-like cry, failure to thrive, microcephaly, facial anomalies, and mental impairment.

EPIDEMIOLOGY:

incidence: 1:50,000
age of onset:
- can be detected in infancy
risk factors:
- sporadic
- F > M

PATHOGENESIS:

1. Background

first described by J. Lejeune et al. in 1963
also called Cat Cry Syndrome, Chromosome 5, Monosomy 5p, or Deletion 5p Syndrome

2. Pathogenesis

partial deletion of the short arm of chromosome 5
- 85% of cases are sporadic de novo deletions
- 15% of cases represent an unequal segregation of a parental translocation
the size of the deletion is variable but includes:
- 5p15.2 - region accounting for most of the phenotypes
- 5p15.3 - critical region accounting for high-pitched cry
if the parental chromosomes are normal, the recurrence risk is 1%

CLINICAL FEATURES:

1. General Manifestations

100% - failure to thrive
100% - mental impairment (IQ rarely above 35)
98-100% - cat-like cry (also weak or high-pitched)
85% - short stature (height <3rd percentile)
60-80% - infantile hypotonia +/- poor muscle tone in childhood
55-65% - abnormal larynx
50-72% - low birth weight (<2,600 g)
50% - feeding difficulties in infancy
45-65% - short neck
30-35% - premature greying of hair in adults
15-30% - congential heart disease (patent ductus arteriosus most common)

2. Craniofacial Manifestations

98-100% - microcephaly
85% - broad-based nose
75-85% - micrognathia
58-85% - low-set or poorly formed ears
70-80% - malocclusion (in older patients)
70-80% - abnormal palate (high & narrow or broad & flat)
68-70% - round face (in infancy)
40% - preauricular tag
25% - facial asymmetry

3. Ocular Manifestations

90-95% - hypertelorism
85-90% - epicanthal folds
75-85% - downslanting or oblique palpebral fissures
60-70% - strabismus (often divergent)

4. Other Manifestations

1. Limbs

80-90% - simian crease
80-90% - distal axial triradius
65-75% - short metacarpals or metatarsals (adults)
65-75% - pes planus (older patients)
25-30% - partial syndactyly

2. Gastrointestinal

30-35% - diastasis reci
25-30% - inguinal hernia

INVESTIGATIONS:

1. Karyotype

simple deletion of a portion of the short arm of chromosome 5 is diagnostic
occasionally a ring formation, de novo unbalanced translocation, or pericentric inversion of chromosome 5 can result in the 5p deletion
some patients may be mosaics

MANAGEMENT:

1. Supportive

no treatment for underlying disorder
multidisciplinary approach
- Paediatrics, ENT, Ophthalmology
- genetic counselling
comprehensive, early stimulation appears to be beneficial

ADDITIONAL REFERENCES:

1. Mary-Louise Buyse, Birth Defects Encyclopedia (1994 Edition), p. 338-339.

2. Jones, K.L., Smith's Recognizable Patterns of Human Malformation 5th Edition), p. 44-45.

3. Baraitser, M. and R.M. Winter, Color Atlas of Congenital Malformations (5th Edition), p. 6.

Pediatric Database - CRI DU CHAT SYNDROME

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