Adnp haplo-insufficient (Adnp+/−) mice or mice CRSIPR/Cas9-edited to present the most prevalent neurodevelopmental ADNP syndrome mutation, p.Tyr718* (Tyr) showed dramatic reductions in male BrdU incorporation, resulting in mutated females presenting higher labeling than males. The gene discussed is ADNP; the disease is ADNP-related multiple congenital anomalies - intellectual disability - autism spectrum disorder.