Fragile X syndrome neurobiology translates into rational therapy

• Fragile X pathophysiological mechanisms were identified in animal models.
• Targeted treatments are being developed based on molecular defects.
• The first clinical trials in fragile X patients have been initiated.

Causal genetic defects have been identified for various neurodevelopmental disorders. A key example in this respect is fragile X syndrome, one of the most frequent genetic causes of intellectual disability and autism. Since the discovery of the causal gene, insights into the underlying pathophysiological mechanisms have increased exponentially. Over the past years, defects were discovered in pathways that are potentially amendable by pharmacological treatment. These findings have inspired the initiation of clinical trials in patients. The targeted pathways converge in part with those of related neurodevelopmental disorders raising hopes that the treatments developed for this specific disorder might be more broadly applicable.