Cri du Chat Syndrome

Cri du chat (5p minus) syndrome results from a deletion of the short arm of chromosome 5, with an incidence of about 1 in 15,000 to 50,000.

About 85 to 90% are de novo (usually paternal origin), and 10 to 15% result from a parental balanced translocation (recurrence risk is higher in these families).

The cat like cry results from laryngeal and neurological abnormalities, and the critical region for the cry is at 5p15.3, while the critical region for intellectual disability is at 5p15.2. TERT is also located in this region, which may contribute to accelerated telomere shortening.

• High pitched, mewing cry in the neonatal period (diminishes by 2 years)
• Low birth weight, microcephaly, hypotonia, and poor suck with feeding difficulty and failure to thrive
• Facial features: round face, hypertelorism, epicanthal folds, down slanting palpebral fissures, low set ears, broad nasal bridge, micrognathia, and a short philtrum; the face lengthens with age
• Severe developmental delay and intellectual disability (the severity correlates with deletion size), and severe speech impairment, with better receptive than expressive language
• Behaviour: hyperactivity, aggression, self-injury (head banging, biting), repetitive movements, and sleep disturbance
• Congenital heart defects (about 15 to 30%; VSD, PDA, ASD), renal anomalies, scoliosis, inguinal hernias, strabismus, hearing loss, dental malocclusion, and constipation and gastro oesophageal reflux
• Life expectancy is near normal for those without severe cardiac or other complications

• Chromosomal microarray detects and sizes the 5p deletion, including terminal and interstitial deletions, and has replaced karyotype and FISH for most testing; karyotype with FISH of both parents is required to identify balanced translocations for counselling. The diagnosis is made in the newborn period if the cry is recognised, but often later. Evaluate: echocardiography, renal ultrasound, hearing and vision tests, spine radiographs, swallow evaluation, and developmental assessment.

• Supportive and multidisciplinary: early intervention including physiotherapy, occupational and speech and language therapy, and educational programmes with visual communication and sign language.
• Feeding: optimise calorie intake, nasogastric or gastrostomy feeding when needed, and reflux therapy (omeprazole 1 mg/kg/day).
• Cardiac: management as per the lesion; routine antibiotic prophylaxis is not needed for most.
• Behaviour: behavioural therapy, environmental modification, and medication for severe self-injury (risperidone 0.25 to 2 mg/day, SSRIs, or naltrexone in selected cases).
• Sleep: sleep hygiene and melatonin 1 to 6 mg.
• Orthopaedic: monitor for scoliosis and hip dysplasia, and provide orthoses.
• Constipation: polyethylene glycol 3350 0.4 to 0.8 g/kg/day.
• Genetic counselling: parental chromosome studies; if one parent carries a balanced translocation, the recurrence risk is higher and prenatal or preimplantation genetic testing is an option.