Rett Syndrome (RTT) is a severe neurodevelopmental condition with breathing disorders, affecting around one in 10,000 female births. Desipramine, a noradrenaline reuptake inhibitor, reduced the number of apneas in Mecp2-deficient mice, a model of RTT. We planned a phase 2 trial to test its efficacy and its safety on breathing patterns in 36 girls with RTT. The trial was a 6-month, multicenter, randomized, double-blind, placebo-controlled study registered with ClinicalTrials.gov, number NCT00990691. Girls diagnosed according to clinical examination and confirmed by genotyping were randomly assigned in a 1:1:1 ratio to receive 2-3 mg/kg Desipramine per day (high Desipramine), 1-2 mg/kg Desipramine per day (low Desipramine), or a placebo. The primary outcome was the change of apnea hypopnea index (AHI), defined by the number of apnea and hypopnea events per hour, assessed at 6 months from baseline. Intention-to-treat analysis was applied. To the publication...