Clinical Characteristics

The vast majority of reported patients with this neurodevelopmental syndrome have intellectual disability of variable severity, although typical intellectual functioning has also been reported. Speech development is particularly affected, and some individuals are non-verbal. There is a shared facial appearance with a triangular-shaped face, a high anterior hairline, eyes which are either deep-set or almond shaped with periorbital fullness, thick nasal alae and flared nostrils, full cheek and a thin upper lip.

Variably present neurodevelopmental features include epilepsy, gait /balance abnormalities, abnormal neuroimaging, spasticity and autistic spectrum disorder.

Most patients are born with normal growth measurements but postnatal growth delays and significant difficulties with feeding, in some cases requiring tube feeding, have been reported. Some patients have generalized hypermobility and minor ophthalmological abnormalities. Recurrent infections, mostly bacterial and affecting the respiratory system may be noted, in some cases requiring hospitalization.

Other less frequently observed features include minor digital anomalies, genitourinary abnormalities including unilateral renal agenesis, pigmentary abnormalities, scoliosis, abnormal bone mineralization and Pierre Robin Sequence with cleft palate.