Uniprot Description An autosomal dominant neurodevelopmental disorder characterized by infantile-onset global developmental delay, severe to profound intellectual disability, mildly delayed walking with broad-based and unsteady gait, and absence of meaningful language. Patients have features of autism, with repetitive behaviors and poor communication, but usually are socially reactive and have a happy demeanor. More variable neurologic features include mild seizures, spasticity, and peripheral neuropathy.