CNTNAP2 and Ataxia: Given the lack of typical Pitt-Hopkins craniofacial features and hyper-breathing patterns in most patients, it has recently been proposed that biallelic loss of CNTNAP2 results in a disorder called “CASPR2-deficiency neurodevelopmental disorder (NDD)”, which includes severe ID, early infantile seizures, language regression, variable presence of autistic features, hyporeflexia and ataxia (Rodenas-Cuadrado et al. 2016).