Dr. Butler is a Professor of Psychiatry and Pediatrics and Director, Division of Research, Department of Psychiatry and Behavioral Sciences at University of Kansas Medical Center. His research interests include the genetics of obesity with emphasis on Prader-Willi syndrome and obesity-related disorders, autism, psychiatric and behavioral genetics, genotype-phenotype correlations and the natural history and delineation of rare and uncommon clinical genetics syndromes. He has conducted research on Prader-Willi, Angelman and Fragile X syndromes, the genetics of autism and obesity and delineation of genetic disorders. 

He is board-certified in Clinical Genetics and Clinical Cytogenetics and became a Founding Fellow of the American College of Medical Genetics and Genomics (ACMG) in 1993.  He is Chairperson of the Scientific Advisory Board of the Prader-Willi Syndrome Association (USA) and received the Lifetime Achievement Award in 2008.  He has published over 400 research articles, multiple book chapters and edited several journal issues and two textbooks.