The purpose of this research study is to see if melatonin improves sleep and the sleep-wake patterns (also known as circadian rhythm) in children, teenagers, and young adults (ages 11-30) with at-risk symptoms. Melatonin is naturally produced in the brain and controls sleep-wake patterns. At-risk symptoms can be feeling like you do not want to do be around other people as much, difficulties with focus, and having beliefs that most people around you don't have. At-risk symptoms can also be experiences like having jumbled up thoughts, your mind playing tricks on you, or seeing or hearing things that are not there. To see if melatonin changes sleep in youth with at-risk symptoms, we are giving some youth with at-risk symptoms a melatonin pill and some a placebo (a pill without any medication in it) for 6 months.

We are looking at how infants and young children breathe in different positions. This will help us understand how children with different types of lung hypoplasia breathe and how the lung changes and grows. To do this, we will measure regional lung ventilation by electrical impedance tomography (EIT) in three positions: lying on the back, right- and left-side in children with pulmonary hypoplasia and in healthy children without lung disease. EIT has been well established as a safe, non-invasive, radiation free method of assessing regional lung ventilation. There is no compensation available for this study.

Children and adults with Beckwith-Wiedemann syndrome may be at increased risk for sleep apnea than other children. This risk may be due to a larger tongue size, but currently it is not known how to predict who need to be evaluated for sleep apnea. Some people with Beckwith-Wiedemann syndrome have tongue reduction surgery, but the effect of this procedure on sleep apnea is not known. This study seeks to understand how the upper airway anatomy contributes to sleep apnea in people with Beckwith-Wiedemann syndrome, including after tongue reduction surgery in people who have that procedure. The study includes a physical exam, medical record review (including surgical history), and upper airway MRI. For those participants who have not had a clinical sleep study, one will be done as part of this study.

This study seeks to understand why some babies born with a small jaw (micrognathia) have sleep apnea and/or trouble growing and others do not. By enrolling healthy babies, we hope to get a better understanding of how infants breathe during sleep and grow over the first months of life. This observational study involves two study visits that each include an overnight sleep study and some other non-invasive tests.