This white paper was produced from the McPosium sessions that were conducted during the 2016 Phelan-McDermid Syndrome Foundation International Conference.  The McPosium was a custom designed symposium to address the issues most pressing to our families.  The sessions were delivered in a format of 20 minute presentations, 20 minute small group discussions and 20 minute panel question and answer sessions.  The McPosium sessions were recorded, and are available on our YouTube channel.  This white paper was authored by Lauren Schmitt, PhD and Geraldine Bliss, MS, and summarizes the discussions during the small group session on Natural History.  It is intended to give researchers insight into topics of interest to families of all ages.  The entire series of white papers are available in the Resource Library.