Asking the Expert: Jeanne Theis PhD

Sep 26, 2018 | Stephen Rowley | @sjrowley


My name is Gabrielle Wanek and I’m an intern here at Mayo Clinic’s Todd and Karen Wanek Program for Hypoplastic Left Heart Syndrome. I had the opportunity to interview Jeanne Theis, one of the team members within the research program, to learn more about the work being done here.


Gabrielle: Thanks for taking the time to chat with me! So, Jeanne, can you please explain what you do?

Jeanne: I study the DNA that comes from humans. I’ve been studying the genetics of cardiovascular disease for the last fifteen years or so. I’ve studied the genetics of cardiomyopathy, different arrhythmias, and even spontaneous coronary artery dissection but right now I am 100% dedicated to studying HLHS. I’ve been working with Dr. Tim Olson for the last ten years. Dr. Olson is the director of the Cardiovascular Genetics lab here at Mayo Clinic.

Gabrielle: What exactly are you looking for in the DNA?

Jeanne: There are three billion letters that make up our DNA sequence. Within those three billion letters, there are about three million that are unique to each person. Those three million are variations that determine hair color, eye color, skin color, height, etc. Half of those come from mom, half come from dad and each individual has some changes that are unique to them. We are interested in looking at all of these changes to identify those that are associated with HLHS. We have a family centric approach, because we also sequence mom and dad to see how the genes are passed along. We look at those changes and we start to explore how common they are and whether there could be a link to HLHS.

Gabrielle: How long does it take to sequence DNA from the participants?

Jeanne: Overall it takes a couple weeks to sequence the DNA fully. The first thing that we do when we get a blood or saliva sample is extract the DNA and ensure we have enough available for genetic sequencing.  If we have the right amount, it is then put on the sequencer and the DNA sits on it for a week where it’s constantly having data collected.

Gabrielle: What do you enjoy most about your job?

Jeanne: I love the people who I work with, not just those who work in our genetics core but with everyone in the program. Our dynamic team is made up of a group of brilliant people which includes physicians, geneticists,  stem cell biologists,  bioinformaticians and many additional areas of expertise. What’s refreshing to me is that it’s a very collaborative environment. Here in this program, it's nice knowing that you can be vulnerable, admitting something that you just don’t know. It’s just being in the midst of amazing people and being able to interact with each other without much tension.

My second favorite thing about this job is teaching. I’ve been really lucky within the program to be able to teach not only at lab meetings, but also giving genetics 101 talks to people that want to understand more. I had a young girl come up to me after one of these talks and say that she understood everything that I said which was a gratifying moment for me. I feel really lucky that I have those opportunities.

Gabrielle: What do we know about the genetics of HLHS?

Jeanne: In a nutshell, there is no single common gene. With HLHS there’s no single change that’s going to be accountable. I think there are multiple changes that come together to cause it. We have sequenced the entire genome for over 150 participants with HLHS to help us further our understanding of key genetic changes related to HLHS. It’s very complicated, but we are getting a lot smarter. We have a lot of data that needs to be looked at and tested with the fruit flies, and we continue to learn more with each additional sequence.

For anyone interested in learning more about HLHS and the genetics research, email our program at

Interested in more newsfeed posts like this? Go to the HLHS blog.

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