Wen-Hann Tan is a clinical investigator and geneticist at Boston Children's Hospital with an expertise in the design and execution of natural history studies, patient registries, and clinical trials in rare monogenic disorders. He is currently the PI of a multi-center natural history study of Angelman syndrome, a co-investigator in the Bohring-Opitz syndrome and ASXL-related disorders Registry led by his mentee, Dr. Bianca Russell of University of California, Los Angeles, and a site PI of multiple industry-sponsored clinical trials in Angelman syndrome as well as a first-in-human gene therapy trial in OTC deficiency. He serves on the Scientific Advisory Committee of the Angelman Syndrome Foundation, and on the advisory board of the Bohring-Opitz Syndrome Foundation and the ASXL Rare Research Endowment Foundation.