ADNP and ADNP-related multiple congenital anomalies - intellectual disability - autism spectrum disorder: On the other hand, decreases in ADNP levels have been linked with diminished dendritic spines and synaptic plasticity in mice [13,38] and cognitive deficiencies in mice [13,38] and humans, with most if not all ADNP syndrome patients suffering from intellectual disabilities [18,19,20,39].