Cri du chat syndrome: Changing phenotype in older patients

The cri du chat syndrome or 5p deletion syndrome is a well-delineated clini cal entity and has an incidence of 1/50,000 in newborn infants. A de novo d eletion is present in 85% of the patients. Ten to 15% are familial cases wi th more than 90% due to a parental translocation and 5% due to an inversion of chromosome 5. Although the size of the deleted segment varies, the crit ical segment that is deleted in all patients appears to be 5p15.2. The clin ical picture is well known in younger patients and includes the typical hig h-pitched cry, psychomotor retardation, microcephaly, growth rate failure, and craniofacial abnormalities including round face, hypertelorism, broad n asal bridge, downward slanting palpebral fissures, and micrognathia. With a dvancing age, the clinical picture becomes less striking. We present seven patients with 5p deletion syndrome, who were between age 16 and 47 years. C omparing their phenotype at several ages, a change of their phenotype was n oted. Some of the clinical characteristics became more evident such as long face, macrostomia, and scoliosis. All patients were severely or profoundly mentally retarded except one patient who was mildly mentally retarded. The diagnosis was difficult to make in some of the patients who were first see n at an older age. In some of them, the craniofacial appearance resembled t hat seen in Angelman syndrome. Most patients had periods of destructive beh avior, self mutilation, and aggression. The clinical diagnosis should be co nfirmed as soon as possible with cytogenetic investigation to provide speci fic support, prevention, and treatment of complications. Therefore, it is i mportant to perform follow-up studies in young children to determine their outcome after infant-stimulation programs. (C) 2000 Wiley-Liss, Inc.