A syndrome that is caused by a variation in the SPEN gene and is characterized by developmental delay/intellectual disability, autism spectrum disorder, anxiety, aggressive behavior, attention deficit disorder, hypotonia, brain and spine anomalies, congenital heart defects, high/narrow palate, facial dysmorphisms, and obesity/increased BMI, especially in females. The disease is Radio-Tartaglia syndrome (MONDO_0859143, a Monarch Disease Ontology entry). Also known as: SPEN-related neurodevelopmental disorder.