David Sweetser, MD, PhD, chief of the Medical Genetics Program at MassGeneral Hospital for Children, explains why it is such an opportune time to be in the field.
Exciting Time for Growing Genetics Program
Throughout his pediatric residency David Sweetser, MD, PhD, struggled to choose between his two passions: genetics and hematology-oncology. Meanwhile, his research interests focused on trying to understand the fundamentals of human development and the genes that control development.
“That kind of research could have gone either way,” Sweetser says.
Sweetser chose a fellowship in genetics, and then became immersed in the research of genes associated with Hirschsprung’s disease, a serious disorder of the bowel. He found some of those genes were also linked to cancer development and was encouraged to focus on hematology-oncology, which led him to a subsequent fellowship in that specialty.
David Sweetser, MD, PhD
Today Sweetser is board certified in Hematology and Oncology, Medical Genetics in Clinical Genetics and Medical Genetics in Clinical Biochemical Genetics. This spring, he was appointed chief of the Genetics Program at MassGeneral Hospital for Children, where he has worked as an attending physician and researcher for the past eight years primarily in pediatric hematology and oncology and with additional work in medical genetics.
“It’s a very exciting time to be in genetics. It’s hard to escape all the news reports about the explosion of knowledge about genetics and how genes are involved, not only in developmental disorders and birth defects, but in almost all aspects of human disease,” Sweetser says.
In the last decade, the field of genetics and genomic testing has expanded immensely and Sweetser says each year the body of knowledge available in the field is easily tenfold greater than the year before.
In the past physicians would at most be able to diagnose a child born with a birth defect, without offering much in the way of treatment. But today Sweetser says, “we can help them at a number of different levels,” due to the existing historical information about genetic disorders and the mounting knowledge of how genes affect development.
“Now there’s an increasing number of treatments for many of these disorders that were otherwise not treatable,” Sweetser says.
Lifelong Genetic Services
The MGHfC Genetics Program diagnoses and treats patients with genetic or metabolic health problems. They evaluate patients with physical anomalies, developmental delays, autism spectrum disorders, metabolic abnormalities and organ dysfunctions to help determine if these findings have an underlying genetic contribution. This information can be helpful for providing treatment, understanding the future course of these individuals and identifying other related conditions that might need attention. It can also help determine if there is a chance other family members or future children may be affected. A core team of genetic counselors, physicians, genetics resident trainees and a nutritionist compile an in-depth family history, evaluate each patient through a detailed physical and determine which tests to order and what treatments may be offered.
Many of the program’s patients are newborns referred from the nursery based on state-mandated newborn screening tests. About 40 percent of the patients treated in the program are adults, because many conditions with genetic causes, such as cardiomyopathies, connective tissue disorders and neurological conditions may not cause problems until later in life.
“Based at Mass General, we are one of the few programs in the country that can offer genetic services through all stages in life, from prenatal counseling and newborns up until well into adulthood,” Sweetser says.
Today nearly 1,000 genetic tests are available and used to diagnose genetic conditions as well as predict risk factors for many conditions. Knowing which tests to order and interpreting their results can be a major challenge, Sweetser says.
“What we’re finding is that there is a massive number of variations in the human population and it’s been extremely difficult to try to sort out which of these variations are actually significant in terms of causing disease,” Sweetser says.
He adds: “This is one field where everybody in it has to commit themselves to staying abreast of all the literature and keep learning,” a charge to which his program is committed.
As the field of genetics expands, the MGHfC program is also growing, under Dr. Sweetser’s leadership.
“My challenges here for the division are to try to expand the services that we offer and to provide a service for the rest of the institution in terms of helping with the diagnosis and understanding of the genetic contributions to diseases and in genetic counseling,” he says.
Dr. Sweetser will oversee an increase in the program’s pediatric staff as well as additional collaboration with specialists who primarily see adults. This year the program is opening a multidisciplinary Turner Syndrome Clinic with specialists in cardiology and endocrinology, and this summer as one of its collaborative efforts, it will launch a Sensory Neuro-Hearing Loss Program with Massachusetts Eye and Ear Infirmary for patients with hearing loss attributed to genetic causes. Sweetser plans to expand the services of the MGHfC Genetics Program to community hospitals.
Meanwhile, Sweetser continues to see patients once a week in the MGHfC Cancer Center, with a special interest in children who have hereditary predispositions to cancer, and he runs his research lab, studying the genes associated with leukemia and searching for new genes associated with tumor suppression and treatment for cancer.
“It’s exciting coming to work,” Sweetser says.