David Cunningham Owens is Professor of Clinical Psychiatry at the University of Edinburgh and honorary consultant psychiatrist, the Royal Edinburgh Hospital. This talk revealed how the development of neuronal communication at synapses is altered in Fragile X Syndrome (FXS). It also examines how basic research into the role of genetics has led to the development of new medicines for treating FXS and hopefully will result in treatment possibilities for some forms of autism. This lecture is part of the Medical Detectives, a series of public lectures that show how keen detective work is still essential for 21st century doctors: http://www.ed.ac.uk/news/events/medical-detectives/ Recorded on 20 September 2012 in the Anatomy Lecture Theatre at the University of Edinburgh.