Dr. Sweetser completed his MD/PhD at Wash. Univ Sch of Med in St. Louis, and Pediatric Residency training at St. Louis Children's Hosp. He did his Medical Genetics Fellowship training at the Wash. Univ Sch of Med in St. Louis and the Univ of Wash in Seattle along with a Biochemical Genetics Fellowship. He subsequently completed a Fellowship in Pediatric Hematology/Oncology at the Univ of Wash. in Seattle. Since 2003 Dr. Sweetser has been at Massachusetts General Hospital seeing patients in Ped. Hem/Onc as well as Medical Genetics and Metabolism and runs a research lab in leukemia and medical genetics. Dr. Sweetser is Chief of the Division of Medical Genetics and Metabolism. Under his leadership the Genetics Program has markedly expanded more than doubling the number of patient visits with new specialty clinics in Turner Syndrome, Hereditary Hemorrhagic Telangiectasia, CHARGE syndrome, a multidisciplinary Sensorineural Hearing Loss Clinic at the MEEI, an Autism Genetics Clinic at the Lurie Center, Pitt Hopkins Syndrome, Pediatric Cancer Predisposition Clinic, as well as a world renown Down Syndrome clinic. Dr. Sweetser has been a leader in the application of whole exome sequencing to clinical diagnostics. Dr. Sweetser is the MGH site director for the NIH sponsored Undiagnosed Diseases Network linking 11 medical centers around the country to accelerate discovery and innovation in the way we diagnose and treat patients with previously undiagnosed diseases.