This is a severe disease with growth and mental
retardation. Death occurs generally in infancy or early childhood. Clinical
features involve all major systems. Cerebral and craniofacial malformations are constant
(Dandy-Walker cyst; subependymal cysts; ventricular dilatation of the brain;
microcephaly; prominent occiput micrognathia; wide cranial sutures and
fontanels; craniosynostosis; facial cleft and cloverleaf skull; short and
up-slanting palpebral fissures; microphthalmia; coloboma; corneal clouding;
hypertelorism; deeply set eyes; low-set malformed ears; tongue
abnormalities; ankyloglossia; cleft lip/palate). Skeleton abnormalities can include
short and webbed neck, hip dislocation, abnormally shaped long bones,
limitation of joint movement, short limbs, and dysplasia of hands and feet.
Other clinical features include heart (ventricular septal defect, atrial septal defect,
patent ductus arteriosus, valve defects, double-outlet right ventricle,
persistent left superior vena cava, endocardial fibroelastosis),
urogenital system (hydronephrosis, duplication of collecting system, microcystic
kidneys, dysplastic kidneys, cryptorchidism, small penis, hypospadias,
hypoplastic labia), and skin (deep palmar and plantar creases, hyperconvex
nails).