Skip to main content

Virtual visit appointments available 7 days a week from 9:00am to 11:00pm. Learn More

COVID-19 Updates

COVID-19 Updates: Get the latest on vaccine information, in-person appointments, virtual visits and more. Learn More


Texas Medical Center

Cancer and Hematology
Phone: 832-824-4643
Fax: 832-825-4038


1102 Bates Ave., Ste. 1570
Houston, TX 77030

Research Laboratory

Donald Williams (Will) Parsons, MD, PhD

Beverly and Daniel C. Arnold Endowed Chair for Precision Medicine, Texas Children's Hospital
Deputy Director, Texas Children's Cancer and Hematology Center
Co-Director, Brain Tumor Program
Co-Director, Cancer Genetics and Genomics Program
Director, Center for Precision Oncology
Professor, Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine


School Education Degree Year
Johns Hopkins University / National Cancer Institute Fellowship Neuro-Oncology 2008
Johns Hopkins University / National Cancer Institute Fellowship Pediatric Hematology/Oncology 2007
Johns Hopkins University Residency Pediatrics 2004
Ohio State University College of Medicine Medical School Doctor of Medicine 2001
Ohio State University College of Medicine PhD Doctor of Philosophy, Pathology 1999


Dr. Donald Williams (Will) Parsons is the Beverly and Daniel C. Arnold Endowed Chair for Precision Medicine at Texas Children's Hospital and Deputy Director of Texas Children’s Cancer and Hematology Center, Baylor College of Medicine (BCM). He is a board-certified pediatric hematologist-oncologist who also serves as Co-Director of the Brain Tumor Program, Co-Director of the Cancer Genetics and Genomics Program, and Director of the Center for Precision Oncology within Texas Children’s Cancer Center. Dr. Parsons has distinguished himself as one of the country’s leaders in the field of cancer genomics and the use of “precision oncology” approaches for the diagnosis and treatment of children with high-risk and relapsed cancers.

After graduating from Princeton University in 1992 with a degree in Chemistry, Dr. Parsons obtained his Ph.D. (Pathology) and M.D. degrees from The Ohio State University College of Medicine. He completed his pediatric residency at Johns Hopkins University and hematology-oncology and neuro-oncology fellowship training at Johns Hopkins and the National Cancer Institute (NCI). He served on the faculty at Johns Hopkins for one year prior to coming to BCM in 2008.

In addition to conducting innovative translational research in pediatric cancer genomics, Dr. Parsons and his team are making important contributions to the clinical care of childhood cancer patients, including establishment of the Precision Oncology Consultation Service at Texas Children’s Cancer Center, which provides recommendations for the use and interpretation of clinical genomic testing for pediatric cancer patients nationwide. He also plays leadership roles within the National Cancer Institute (NCI)-funded Pediatric Brain Tumor Consortium (PBTC) and the Children’s Oncology Group (COG), the world’s largest organization devoted exclusively to pediatric cancer research, including serving as the COG study chair for the NCI-COG Pediatric MATCH trial and as the Genomics and Translational Biology Committee lead for the COG Pediatric Early Phase-Clinical Trial Network (PEP-CTN).

Dr. Parsons actively mentors trainees at all educational levels (including graduate students, postdoctoral fellows, and junior faculty members). He is on the Steering Committee of the BCM Medical Scientist (MD/PhD) training program and is the Director of the Pediatrician-Scientist Training and Development Program, a track of the BCM Pediatrics Residency Program that seeks to mentor future physician-scientists. He received the BCM Department of Pediatrics Research Mentorship Award in 2016.


Organization Name Role
American Association for Cancer Research (AACR) Member
American Society of Clinical Oncology (ASCO) Member
American Society of Pediatric Hematology and Oncology (ASPHO) Member
Children's Oncology Group (COG) Member
Pediatric Brain Tumor Consortium (PBTC) Member
Society of Neuro-Oncology Member

Research Statement

Dr. Parsons’ research has helped to characterize the genetic landscapes of a variety of cancers, including the first identification of IDH1 and IDH2 as critical genes in brain tumors affecting both children and adults (gliomas). His current research primarily focuses on the clinical application of genomic technologies in pediatric cancer care and “precision oncology” strategies for the diagnosis and treatment of children with relapsed and refractory cancers.

Dr. Parsons and Dr. Sharon Plon were the principal investigators of the BASIC3 study (2011-2017), a National Human Genome Research Institute (NHGRI) and NCI-funded Clinical Sequencing Exploratory Research (CSER) program project investigating the utility of clinical tumor and blood exome sequencing for children with newly-diagnosed solid tumors. Results of the BASIC3 study have been presented at numerous national and international scientific meetings, including the American Society of Human Genetics (ASHG), the American Association for Cancer Research (AACR), the American Society for Clinical Oncology (ASCO) and the International Society of Pediatric Oncology (SIOP), and published in journals such as JAMA Oncology, Genome Medicine, and Pediatric Blood & Cancer.

Drs. Parsons, Plon, and Amy McGuire (Director of the Center for Medical Ethics and Health Policy at BCM) are currently leading the NHGRI and NCI-funded Texas KidsCanSeq project as part of the CSER consortium. This study began enrolling both newly-diagnosed and relapsed cancer patients at Texas Children’s Cancer Center in the summer of 2018 and is now expanding to multiple sites around the state for enrollment of more than 1000 patients in order to compare the clinical utility of different types of genomic testing (DNA and RNA mutation panels, exome sequencing, RNA sequencing, and copy number arrays) for the diverse pediatric cancer patients of Texas.

Dr. Parsons is the COG study chair for the NCI-COG Pediatric MATCH study, the first nationwide precision oncology clinical trial for children with relapsed and refractory cancers that opened in July 2017. Pediatric MATCH involves sequencing of patient tumor samples to identify genetic mutations that can serve as targets for molecular therapies, with more than 450 patients screened for “matches” to 10 different investigational drugs as of January 2019. The study also includes analysis of matched patient blood samples to identify inherited mutations related to familial cancer risk.

In addition to these clinical genomics projects, Dr. Parsons’ group is also currently conducting numerous sequencing studies of high-risk and rare pediatric cancers (including a variety of brain tumors, liver tumors, sarcomas, histiocytic disorders, and leukemias), with goals of revealing tumor biology, identifying potential molecular targets for therapy, and facilitating pre-clinical characterization of novel therapeutics.

Dr. Parsons has published more than 60 scientific papers in peer-reviewed journals, including: Science, Nature, the Journal of Clinical Oncology, the New England Journal of Medicine, JAMA Oncology, and Genome Medicine. He has been awarded numerous honors for his research, such as the Peter A. Steck Memorial Award for Brain Tumor Research (2009). Parsons is a Graham Cancer Research Scholar at Texas Children’s Cancer Center and has received funding from multiple sources to support his work on the genetic causes of pediatric cancers, such as the Cancer Prevention Research Institute of Texas (CPRIT), the National Human Genome Research Institute, the National Cancer Institute, Alex’s Lemonade Stand Foundation, the St. Baldrick’s Foundation, the Gillson-Longenbaugh Foundation, the American Brain Tumor Association, the American Society for Clinical Oncology, the Doris Duke Charitable Foundation, the Sidney Kimmel Foundation, and the Sontag Foundation.

Board Certification

American Board of Pediatrics - Hematology/Oncology



Latest Videos

* Texas Children's Hospital physicians' licenses and credentials are reviewed prior to practicing at any of our facilities. Sections titled From the Doctor, Professional Organizations and Publications were provided by the physician's office and were not verified by Texas Children's Hospital.