Robert Nussbaum is the Lloyd (Holly) Smith Distinguished Professor of Medicine, Chief of the Division of Medical Genetics in the Department of Medicine at the University of California, San Francisco, and a member of the UCSF Institute of Human Genetics. His primary research focus is on the pathogenesis of Parkinson disease. His approach is to find the genes responsible for relatively rarer familial forms of the disease as a way of gaining insight into fundamental pathways leading to Parkinson's disease. These pathways then become targets of early diagnostic and therapeutic interventions. Dr. Nussbaum received his undergraduate degree in Applied Mathematics from Harvard College and his MD from Harvard Medical School in the Harvard-MIT Joint Program in Health Sciences and Technology. After residency training in Internal Medicine at Washington University/Barnes Hospital and Medical Genetics training at Baylor College of Medicine in Houston, he joined the Howard Hughes Medical Institute and the faculty of Human Genetics at the University of Pennsylvania where he was promoted to Associate and then Full Professor of Genetics, Pediatrics, and Medicine. He left the University of Pennsylvania in 1993 to help launch the new intramural research program of what is now the National Human Genome Research Institute. It is there that in 1996, he and his colleague Dr. Mihales Polymeropoulos mapped and identified the first hereditary form of Parkinson's disease, that caused by mutations in the gene encoding alpha-synuclein. He left the NHGRI in 2006 to move to UCSF. Dr. Nussbaum is a member of the Institute of Medicine and served as President of the American Society of Human Genetics in 2004.