Observational Study to Investigate the Melatonin and Cortisol Circadian Rhythms of Individuals With Smith-Magenis Syndrome (SMS)

Inclusion Criteria: * A confirmed clinical diagnosis of SMS with a prior positive genetic test result as indicated by a parent/guardian * Informed consent from the patient or the legal guardian/assent provided by the individual with SMS, when possible * Male or female between the ages of 6-50 years of age * History of sleep disturbances * Willing and able to comply with study requirements and restrictions Exclusion Criteria: * Failure to confirm diagnosis of SMS by molecular cytogenetic methods and/or DNA-based mutation analysis of the RAI1 gene * Totally blind with no light perception * Institutionalized or living in an assisted living facility * Unwilling or unable to follow medication restrictions (medications that affect sleep or melatonin secretion) or unwilling or unable to sufficiently wash-out from use of a restricted medication * Any medical condition, as determined by the clinical investigator that would make it unsafe for blood draws (e.g., anemia, blood clotting disorders, anxiety, etc.) * Any other sound medical reason as determined by the clinical investigator