These patients present with short stature, skin
laxity, and failure to thrive (generalized hypotonia and poor sucking
reflex). The main features involve the head and neck (short neck,
trigonocephaly, biparietal widening of the head, metopic craniosynostosis,
microcephaly, agenesis of the corpus callosum, micrognathia, low-set and
posteriorly rotated ears, epicanthal folds, upward slanted palpebral
fissures, strabismus, anteverted nares, flat and broad nasal bridge, short
nose, high arched and deeply furrowed palate, oral frenula, thick anterior
alveolar ridges, macrostomia); the central nervous system (hypotonia,
seizures, psychomotor retardation); the heart (tetralogy of Fallot,
ventricular septal defect, patent ductus arteriosus, Eisenmenger syndrome);
the lungs (abnormal segmentation of the lungs); the gastrointestinal system
(visceral angiomatosis, omphalocele, hepatomegaly); the genitourinary tract
(prominent clitoris and labia majora, cryptorchidism, renal cortical cysts,
hydronephrosis); and the skeleton (hyperextensible joints, fused sternal
ossification centers, scoliosis, anomalous ribs, radial head dislocation,
postaxial polydactyly, clinodactyly, terminal transverse limb reduction,
metacarpal hypoplasia, hip dislocation). Clotting disorders and abnormally placed nipples are frequent findings.
Approximately half of the patients die within the first year of life.