All patients have a characteristic facial
appearance (brachycephaly, midface hypoplasia, prominent forehead, broad
nasal bridge) and a degree of mental retardation. Delayed speech
development, hoarse voice, ocular abnormalities (strabismus, myopia,
microcornea, iris anomalies, cataracts, optic nerve hypoplasia, and retinal
detachment) and a peripheral neuropathy are common. Sleep disorders become
more common during childhood. Decreased or absent rapid eye movement (REM)
sleep has been demonstrated by polysomnography. The syndrome is classically
associated with aggressive outbursts, attention-deficit, attention-seeking
behaviors, and self-harm. However, these patients are eager to please and
respond well to adult attention. A history of infantile hypotonia is often
present. Scoliosis is common (65% of patients). Less-common findings are
congenital heart disease (37% of patients), major urogenital anomalies
(35% of patients), hypothyroidism (29% of patients), immunoglobulin
deficiencies (23% of patients), and cleft lip/palate (9% of patients).
Behavioral and sleep disturbances may respond to treatment with
carbamazepine or selective serotonin reuptake inhibitors.