ARHGEF9 and Down syndrome: These findings parallel the human reports of disrupted sleep-wake cycle [4], and abnormal discharges during NREM [4] in patients with mutation in ARHGEF9. Again, sleep dysfunction is relatively widely reported in ID syndromes, with core sleep abnormalities in Down Syndrome including prolonged latency to sleep, sleep fragmentation, and reduced time spent in REM [49, 50].