Currently, there is no clinically available genetic-based treatment for RAI1 (Retinoic Acid-Induced 1) -related disorders other than symptomatic management and there are no established clinical or molecular biomarkers that could be used as measures for the efficacy of therapy in future treatment studies. Biomarkers are measures of what is happening inside the body, shown by the results of laboratory, imaging or other tests. Biomarkers can help doctors and scientists diagnose diseases and health conditions, monitor responses to treatment and see how a person's disease or health condition changes over time. The goal of this observational and laboratory study is to develop clinical, neurophysiology and molecular biomarkers in RAI1-related disorders. The main question\[s\] it aims to answer are: * to characterize the disease features more precisely and analyze the differentiating and overlapping features of RAI1-related disorders (Smith-Magenis syndrome and Potocki-Lupski Syndrome) * to identify clinical, neurophysiology, and laboratory biomarkers that differentiate RAI1-related disorders one from another. Participants will have to complete: * a clinical examination * a blood draw * a skin biopsy (optional) * a sleep study Researchers will compare patients' blood to control group's blood for biomarker studies.