We all have about 24,000 genes. How those genes are structured and interact can determine our current health and our future health.
Modern medicine includes specialists in this field called Clinical Geneticists. In today’s TPR Lifeline, Bioscience-Medicine reporter Wendy Rigby talks to Baylor College of Medicine’s Scott McLean, MD, about his work at the Children’s Hospital of San Antonio.
Rigby: Dr. McLean, what is clinical genetics?
McLean: Clinical genetics is the medical specialty that uses genetic information to improve your genetic health or to understand the basis for a variety of medical conditions.
Those of us who have had children in Texas know that while you’re still in the hospital, you get some genetic testing done. What is that called and what are you looking for?
We have newborn screening which is actually a blood test that is given to all babies 24 and 48 hours of age. The blood test involves collecting that blood on a piece of paper, filter paper, and sending that to the Texas State Department of Health Services in Austin where they do a series of tests.
This is the foot prick?
This is where you prick the heel. It seem awfully cruel. Babies cry. Parents don’t like it. But it’s actually a wonderful test because it allows us to screen for over 50 conditions.
Give us some examples. What are some of the genetic conditions we might have heard of?
Well, the initial condition that was screened for in newborn screening in the United States was PKU which stands for Phenylketonuria. This is a condition that results in intellectual disability and seizures. We can change that outcome if we are able to identify the condition early enough and change the diet.
Let’s say a child comes in to Children’s Hospital of San Antonio. Doctors are having trouble figuring out what’s going on. Are you called in to consult?
Most of our patients that we see in the outpatient clinic are sent to us by consultation from physicians in the community or from nurseries, neonatal intensive care units. They range from situations such as multiple birth defects, to autism, intellectual disability, seizures, encephalopathy, blindness, deafness. There’s a whole gamut of reasons that folks come to see us.
When these children become grownups, does that information that you’ve learned about them help them out if they’re planning to have their own children in the future?
So when pediatric patients make the transition from pediatric care to adult care, it’s very common for information and ideas to get lost. And we certainly would hope that people remember that. Sometimes when we have identified a situation in a little baby, I tell the parents that I want them to put a sticky note on the last page of their baby book so that when they are showing the baby book to their child’s fiancée and they get to the last page, it reminds them you need to go back to see the geneticist because there’s this genetic situation that you need to have a nice long chat about so that you can plan your family as carefully as possible.
Right. So the work you’re doing today could help someone 30 years in the future.
Well, genetics is a very unique specialty in that regard because when we see a patient we’re not thinking about their next year of life or their next two years of life or the next month. We do think about that. But this is a lifelong diagnosis and a lifelong situation. So I often joke with my patients that I’m going to try to put them on the 90-year plan. What we figure out now about their genetics is going to be helpful for them throughout their entire lifespan, at least up until 90 years. And then after that they’re on their own. But we’ll get them to 90.
So it’s an exciting time to be in the field.
Very exciting. I think the era of gene therapy which for many people we thought was never going to happen, it’s very promising because we have new technologies that I think are going to allow for advances in that area.
Dr. Scott McLean with Baylor College of Medicine and the Children’s Hospital of San Antonio, thanks for the information.
You’re quite welcome.
