“…and 1 (Kappy & Ganong, 1994) and 23 and 1 (Bridges et al , 1994). There is a predisposition for the development of CPP in children with neurofibromatosis type 1 (2·4 -5%: Habiby et al , 1995Habiby et al , , 1997Cnossen et al , 1997;Carmi et al , 1999;Virdis et al ., 2000), in children with hydrocephalus (10 -11%: Abdolvahabi et al ., 2000;Brauner et al , 1987a;De Luca et al , 1985;Kaiser et al , 1989;Lopponen et al , 1996;Siddiqi et al , 1999;Tomono et al , 1983), in children with meningomyelocele (5-33%: Hunt, 1990;Meyer & Landau, 1984;Trollmann et al , 1996Trollmann et al , , 1998, in children with neonatal encephalopathy (4·3%: Robertson et al , 1990), and in children after low dose cranial irradiation (Brauner et al , 1984(Brauner et al , , 1999Ogilvy-Stuart et al , 1994). An association of Williams-Beuren syndrome with an increased frequency of CPP was recently reported (Scothorn & Butler, 1997;Cherniske et al , 1999;Partsch et al , 1999b).…”