Top Docs Q&A: Diana Bianchi
This doc is using DNA sequencing to make prenatal testing more accurate.
This post is part of our Top Docs Q&A series where we ask a physician who was selected as one of our Top Docs questions about their field, life as a doctor, and practicing in the Greater Boston area.
Name: Diana Bianchi
Hospital Affiliation: Tufts Medical Center
Title: Executive director of the Mother Infant Research Institute at Tufts Medical Center; Natalie V. Zucker Professor at Tufts University School of Medical
Field: Clinical genetics
Specialty: Fetal abnormalities, prenatal genetic diagnosis
Diana Bianchi is a geneticist who has spent her career developing more accurate, non-invasive methods of diagnosing prenatal genetic conditions. To accomplish this, she is using DNA sequencing to detect genetic abnormalities in the fetus. Bianchi is also working to develop a prenatal treatment for fetuses with Down syndrome.
How did you first choose clinical genetics?
In high school I did my senior thesis in a laboratory, and I became fascinated by chromosomes. However, clinical genetics did not exist as a specialty when I was in medical school, so I had to wait till the 80s to become an official geneticist. At the time it was considered to be subspecialty of pediatrics, so that’s where I did my original training.
What do you love most about the field?
It’s constantly changing, so for a life long learner it’s the perfect field. I love how the kinds of patients and cases I see are always different. Also, the fact that I can take care of a pregnant woman and then have the opportunity to see that child grow up is really rewarding.
In the time you’ve been practicing how have you seen the field of clinical genetics change?
First is that it’s now a recognized specialty within medicine. Secondly, it has gone from treating just pediatric patients to people of all ages. The third change is the genetic technology. The Human Genome Project was completed in 2003, and we now use it everyday to diagnose and manage our patients.
What are the latest advancements in your field?
The area that I do a lot of work in is prenatal testing. We can now read the DNA that’s floating around in a pregnant woman’s bloodstream and use that information to determine if the baby is at risk for one of the major chromosome abnormalities. This is a test that was just released in 2011, and now it has totally revolutionized prenatal screening and diagnosis.
Why is this DNA testing better than the standard prenatal testing that pregnant women receive now?
The standard of care consists of a combination of blood tests which measures proteins and ultrasound tests, both of which determine your baby’s risk of Down syndrome or Trisomy 18. The problem is that there’s around a 5 percent chance that you will receive a false-positive result. This means that the test result comes out abnormal but that the baby does not actually have Down syndrome. This causes a lot of anxiety, and it also requires the woman to go to a genetic counselor to receive information about invasive diagnostic procedures for more accurate results. Understandably, most women don’t want to have a needle put into their wombs, which is what these subsequent tests entail, especially because there is a slight risk of miscarriage. These non-invasive DNA tests perform so accurately, though, that it’s reducing the need for these invasive tests by about 50 percent.
If these DNA tests are so accurate then why aren’t they more widespread?
The tests are still on the expensive side, because the DNA sequencing technology is more expensive. So before they can be offered to all pregnant women, the costs need to come down, and we believe that they will eventually.
Why do you think it’s important for women to know about these potential abnormalities beforehand?
There’s a big benefit to knowing ahead of time so you can educate yourself about the condition, and you can plan to deliver your baby at an academic medical center. Eventually we are hoping that there will be specific fetal individualized treatments, which are drugs tailored to the individual genetic variation of the patient, to prenatally treat the baby for genetic abnormalities.
Is this something you are developing now?
For the past three years we have been actively working to find prenatal treatments for fetuses with Down syndrome. We found that the fetuses with Down syndrome have problems with oxidative stress, which we think results in the death of nerve cells in the brain. To prevent this we’ve tested some antioxidants, which are pre-existing FDA approved drugs, on human-fetal cells. Thus far, they’ve definitely reduced the oxidative stress in the cells. We also have mice that have been bred to have the same abnormalities that humans have with Down syndrome, and we have some preliminary evidence that we can already improve their learning, memory, and behavior.
What is your hope for the future of clinical genetics?
My biggest hope is that women will be able to have healthy pregnancies armed with the knowledge of potential problems, and they will have the option, if they so chose, to start treatment prenatally. I believe this could be a reality in the next five years.
What is your favorite part about practicing in Boston?
Boston is really the hub of the medical universe. I think the intellectual breadth of my colleagues in Boston is really unparalleled to anywhere else in the world.