<b>Background</b>: Helsmoortel-Van der Aa syndrome (HVDAS) is a rare multisystemic neurodevelopmental disorder caused by pathogenic variants in the <i>Activity-Dependent Neuroprotective Homeobox Protein (ADNP)</i> gene. Here, ADNP is linked to ADNP-related multiple congenital anomalies-intellectual disability-autism spectrum disorder.