RT Journal Article SR Electronic T1 β1-adrenergic antagonists improve sleep and behavioural disturbances in a circadian disorder, Smith-Magenis syndrome JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 586 OP 590 DO 10.1136/jmg.38.9.586 VO 38 IS 9 A1 Hélène De Leersnyder A1 Marie-Christine de Blois A1 Michel Vekemans A1 Daniel Sidi A1 Elisabeth Villain A1 Catherine Kindermans A1 Arnold Munnich YR 2001 UL http://jmg.bmj.com/content/38/9/586.abstract AB Smith-Magenis syndrome (SMS) is a clinically recognisable contiguous gene syndrome ascribed to interstitial deletions of chromosome 17p11.2. Patients have a phase shift of their circadian rhythm of melatonin with a paradoxical diurnal secretion of the hormone. Serum melatonin levels and day-night behaviour were studied in nine SMS children (aged 4 to 17 years) given acebutolol, a selective β1-adrenergic antagonist (10 mg/kg early in the morning). Cardiac examination, serum melatonin, motor activity recordings, and sleep diaries were monitored before and after drug administration. The present study shows that a single morning dose of acebutolol suppressed the inappropriate secretion of melatonin in SMS. A significant improvement of inappropriate behaviour with increased concentration, delayed sleep onset, increased hours of sleep, and delayed waking were also noted. These results suggest that β1-adrenergic antagonists help to manage hyperactivity, enhance cognitive performance, and reduce sleep disorders in SMS.