Helsmoortel-Van der Aa syndrome is a complex neurodevelopmental disorder characterized by intellectual disability, autism spectrum disorder, severe speech and motor delay, and dysmorphic facial features. Common health problems are congenital heart disease, brain abnormalities, seizures, visual impairment, short stature, hypotonia, hormonal deficiencies, gastrointestinal problems, feeding difficulties, sleep disorder and behavioral problems.
The disease is the consequence of a single error in one of our genes called ADNP gene. Most mutations occur spontaneously in the child, meaning that none of the parents carries the mutation. It is therefore unlikely, but not impossible, that multiple patients are present in a single family. Mutation in this gene are responsible in at least 1 to 2 per 1000 children with autism and intellectual disability. This means that it is one of the more frequent causes of syndromic autism.