Exploring the Clinical Spectrum of CNTNAP2-related Neurodevelopmental Disorders: A Case Series and a Literature Appraisal.

Biallelic pathogenic variants in CNTNAP2, a gene encoding the contactin-associated protein-like 2, have been reported in patients with various clinical presentations including intellectual disability (ID), autistic spectrum disorders (ASD), psychiatric disorders, and focal epilepsy rarely associated to focal cortical dysplasia. We report four children carrying novel biallelic CNTNAP2 pathogenic variants. They present global developmental delay, psychiatric disorders, and focal epilepsy. All patients displayed brain MRI abnormalities consistent with focal temporal dysplasia. One patient had a temporal resection before the availability of genetic testing. Focal cortical dysplasia represents a frequent finding related to focal refractory epilepsy in CNTNAP2 affected patients, and surgery seems to be ineffective in this setting. The genetic testing could therefore be impactful on treatment choices in refractory focal epilepsies.