Focus Areas in the Genomic Medicine Cycle
Major leadership positions

Chief of Medical Genetics and Metabolism, MGH

MGH Site Director Undiagnosed Diseases Network

Co-Director Pitt Hopkins Syndrome Clinic, MGH

MGH Site Director HMS Genetics Training Program

Co-Director Harvard Affiliated Hospitals National Center of Rare Diseases Center of Excellence

MGH Department/Division

Medical Genetics and Metabolism

MGH Unit(s)



The Sweetser Lab has two areas of focus. One is rare disease work. Our work with the Undiagnosed Diseases Network takes a deep dive into phenotyping, evaluations, and genome sequencing, and functional characterization to identify novel genetic disorders. We also have focused projects in Pitt Hopkins syndrome, IQSEC2, and epileptic encephalopathies with Natural History studies and creating patient derived stem cell models. The second area of research seeks to characterize the leukemic stem cell niche and develop targeted cancer therapies.

Priority Projects

  1. Disease Gene Discovery. As MGH site Director of the Undiagnosed Diseases Network, Dr. Sweetser leads a team that evaluated patients with challenging disorders that have eluded diagnosis with exhaustive clinical workups. Patients undergo a comprehensive evaluation with a thorough medical record review, clinical phenotyping, laboratory testing and imaging as needed, clinical evaluations, and genome sequencing. Sequence variants of potential significance are identified, and through contact with collaborators around the world, model organism cores, and in many cases functional characterization through in vitro modeling in the Sweetser lab we can often identify known or known genes causing these disorders. Nearly a dozen novel genetic disorders have been identified by the Sweetser lab in the last 10 years.
  1. Neurodevelopmental Disorders. The Sweetser lab has focused on several neurodevelopmental disorders – Pitt Hopkins Syndrome, IQSEC2, CELF2, and epileptic encephalopathies running Natural History studies and developing patient derived stem cell models to better understand the pathogenesis and to develop novel targeted therapies.
  1. Characterization of the Leukemic Stem Cell Niche. The Sweetser Lab has also been investigating how leukemia and other cancers develop with the goal of developing novel, safer, and more effective therapies. Current work in this area involves characterization of the leukemic stem cell niche and potential targets for development of targeted therapeutics. The lab uses both in vitro as well and murine models in these assays

Lab Members

Evangelos TheodorouEtheodorou [@] .mgh.harvard.eduRole: Staff Scientist
Lauren BriereLbriere [@] partners.orgClinic Coordinator of the Undiagnosed Diseases Network
Lab/Contact Telephone




Primary Email

dsweetser [@]

Lab Website