Cri du Chat syndrome: Deletion 5p- syndrome; chromosome 5 short arm deletion

Cri du Chat syndrome was first described by Lejeune et al (1963). Early research described the prevalence of Cri Du Chat syndrome as about 1 in 50,000 live births (Neibhur, 1978), although more recent estimates suggest a greater incidence of 1 in 37,000 live births (Higurashi, Masaaki et al 1990).

The hallmark cat-cry is a core feature of Cri du Chat syndrome and is still regarded as an important early clinical diagnostic feature in most but not all individuals. Many infants tend to be of low birthweight and show marked hypotonia. Feeding difficulties are common and the associated failure to thrive may be the initial clinical presentation. Some infants may require enteral feeding, a process which may have to continue for several years. Certain facial and head abnormalities are also over represented: microcephaly, micrognathia, rounded face, macrostomia, hypertelorism with downward sloping palpebral fissures, low set ears, broad nasal ridge and short neck. Structural laryngeal abnormality and hypotonia are thought to be responsible for the cat-like cry.

The phenotype tends to become less striking with advancing age which may result in diagnostic difficulty in these circumstances; conversely, other features tend to become more apparent: long face, scoliosis and macrostomia (Van Buggenhout et al 2000). In addition to the major health problems already described, children with Cri du Chat syndrome are very prone to develop recurrent upper respiratory tract infections, otitis media and dental problems. In contrast, the prevalence of epilepsy is very low compared to heterogeneous samples of people with severe learning disabilities (Cornish and Pigram 1996). Once patients manage to negotiate childhood, they can probably expect to live a normal life-span.

Psychological and behavioural characteristics
The early reports on the syndrome suggested that profound learning disability was a cardinal feature of the syndrome, presenting in all individuals with a 5p deletion. However, recent findings indicate that in children with typical Cri du Chat, IQ predominantly falls into the moderate to severe learning disability range but that there is a crucial discrepancy in the pattern of language functioning with children displaying better receptive than expressive language (Cornish, Bramble et al 1999; Cornish and Munir 1998). These findings extend previous research that discovered 'language delay' to be a deviant feature of the syndrome by highlighting a particular strength within their cognitive profile. Even in children with very minimal speech, studies have shown that many can use basic sign or gestural language for communication (Carlin 1990).

Self-injurious behaviour appears to be very common in Cri du Chat syndrome (Dykens and Clarke 1997; Collins and Cornish 2001) most notably head banging, hitting the head against body parts, and self-biting all reaching a plateau in late childhood and then remaining constant throughout early adulthood. Clinical hyperactivity is also known to be over represented in children with the syndrome (Dykens and Clark 1997) and is further compounded by a high incidence of chronic sleep problems and restlessness.

Inheritance patterns
Most cases of Cri du Chat syndrome are sporadic (eighty-five per cent) while ten to fifteen per cent of cases are familial with the overwhelming majority due to parental translocations.

Prenatal diagnosis
Chorionic Villus Sampling at ten to twelve weeks and amniocentesis at fifteen to sixteen weeks are available.

Medical text written July 2001 by Dr K Cornish and Dr D Bramble, Consultant Child and Adolescent Psychiatrist, Nottingham University, Nottingham, UK. Last reviewed October 2005 by Professor K Cornish, Canada Research Chair in Neuropsychology and Education, McGill University, Montreal, Canada.

Further Online Resources
Medical texts in The Contact a Family Directory are designed to give a short, clear description of specific conditions and rare disorders. More extensive information on this condition can be found on a range of reliable, validated web sites and links to them are included in the CD-ROM version of this Directory. Further information on these resources can be found in our Medical Information on the Internet article.

CRI DU CHAT SYNDROME SUPPORT GROUP

Cri du Chat Syndrome Support Group
5 Latimer Drive
Basildon SS15 4AD
Tel: 0845 094 2725
e-mail: info@criduchat.co.uk
Web: http://www.criduchat.co.uk

The Group is a National Registered Charity No. 1044942, established in 1987. It aims to provide support and friendship to families and carers throughout the UK and Ireland. The Group also seeks to raise awareness of the syndrome amongst the medical profession, parents, carers and the public. It organises an annual family weekend conference for families and professionals, encourages local area gatherings and produces two newsletters per annum. The Group is in touch with over 200 families.

Group details last confirmed October 2007.