Two new cases of nonepileptic neurodevelopmental disorder due to GRIN2B variants and detailed clinical description of the behavioral phenotype. Issue 2 (15th December 2021) - Buonuomo, Paola Sabrina; Mastrogiorgio, Gerarda; Alfieri, Paolo; Terracciano, Alessandra; Cesario, Claudia; Rana, Ippolita; Macchiaiolo, Marina; Veronika Gonfiantini, Michaela; Vecchio, Davide; Cristina Digilio, Maria; Lisa Dentici, Maria; Cumbo, Francesca; et al.