Most individuals affected with this condition have intellectual disability or developmental delay. The degree of delay is quite variable, with some having only mild difficulties and other with more severe delays. Speech development is particularly affected, and some individuals are non-verbal. On careful examination, Individuals with this condition have a similar facial appearance.
Other neurological features include epilepsy, difficulties with walking / balance, differences on brain MRI, increased tone (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 (highly flexible joints) 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 differences of the fingers and toes, abnormalities in the kidneys / urinary tract, scoliosis and cleft palate.