The purpose of this study is to characterize the circadian rhythm disruption experienced by patients as determined by plasma melatonin, cortisol, and other circadian analytes

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

Smith-Magenis patients