JUDY WOODRUFF: Finally tonight, living with Parkinson’s disease. That’s the subject of a new Frontline documentary airing tonight on many PBS stations. It tells the personal story of correspondent Dave Iverson, who, like his father and brother, was diagnosed with Parkinson’s.
In chronicling his own story, he also reports on some of the latest research about causes and treatment. Here’s an excerpt from the documentary looking at his family’s history.
DR. MATTHEW FARRER, Mayo Clinic, Jacksonville: But don’t touch the fingers.
DAVE IVERSON, correspondent: Given my family’s story, I couldn’t help but wonder if Parkinson’s was genetic, so I enrolled in a study at Jacksonville’s Mayo Clinic.
Until recently, the idea that your DNA might cause Parkinson’s was considered unlikely. But geneticists like the Mayo Clinic’s Dr. Matthew Farrer are now taking a closer look at the role of the family tree.
DR. MATTHEW FARRER: There was no genetics in Parkinson’s disease 10 years ago, none. This century, in the 21st century, it’s genetics. The genetics provides molecular clues, rational clues, as to what’s going on in the disease process.
DAVE IVERSON: In the past 10 years, Farr and other geneticists have found mutations that cause Parkinson’s in six different genes, and they’re looking for more.
STUDY WORKER: Just tell me about your family and I can just draw them in.
DAVE IVERSON: OK. So there is me, and I have Parkinson’s.
STUDY WORKER: All right.
DAVE IVERSON: And so does one of my brothers. And my father had Parkinson’s.
DAVE IVERSON: And beyond individual family ties, geneticists are now tracking Parkinson’s genes in whole populations.
STUDY WORKER: It’s my understanding that you come from Norway, background is Norwegian.
DAVE IVERSON: Yes, my grandfather was born in Norway, in Barafik, Norway.
STUDY WORKER: Grandfather on what side?
DAVE IVERSON: My father’s.
STUDY WORKER: Father.
DAVE IVERSON: In 2004, Mayo scientists helped discover the most common Parkinson’s mutation in the Lurk 2 gene. They’ve now traced it to several locations, including North Africa, near the ancient site of Carthage and, oddly enough, to my ancestral home, the coast of Norway.
DR. MATTHEW FARRER: It spread to Norway, we think, because of Viking occupation. There was Vikings living in and around Carthage in around 1000 A.D., and this particularly mutation is quite common on the northern coastline of Norway.
DAVE IVERSON: My grandfather’s birthplace is on the Norwegian coast next door to Norway’s first Viking settlement. So did my own family’s Parkinson’s saga begin a thousand years ago when some sea-faring relative came calling in Carthage?
New focus on genetics
JUDY WOODRUFF: Dave Iverson talked with our Jeffrey Brown this afternoon.
JEFFREY BROWN: Dave, as we see from that clip, one road you went down was your own family history. So what has changed about our understanding about the role of genetics in Parkinson's?
DAVE IVERSON: Well, as Matt Farrer said in that clip, Jeff, it wasn't until fairly recently that we thought genetics played a role in Parkinson's disease at all. In fact, I can remember decades ago talking with my father's neurologist who said, "There's no need to worry. Parkinson's isn't something that has any sort of familial connection."
So it's only been quite recently that we've discovered still rather rare that sometimes in families there are these genetic tendencies.
JEFFREY BROWN: And you're still -- how does all that play against what we have looked at over, well, of more than a decade now about environmental causes?
DAVE IVERSON: Well, it may be that both things are true. It's still thought that largely Parkinson's is an environmentally caused condition. They're looking at many possibilities, including, for example, exposure to pesticides.
And there's some big studies going on right now in the central valley of California, which is a large agricultural area, also in North Carolina and Iowa, trying to map out whether or not there's a connection between whether or not people are exposed to pesticides have a higher incidence of Parkinson's disease. And there's some real thought that that may likely be true.
But it also may be that there could be an interaction between genes and the environment. In other words, you could have a genetic propensity for getting Parkinson's, but you might not get it. You might be totally fine for your entire life unless you're exposed to a particular toxin and that would then trigger the disease.
As one of the researchers says in this story, there's an old saying which is that genetics loads the gun, but environment pulls the trigger. And that may be part of what plays out with Parkinson's.
Exercise may slow Parkinson's
JEFFREY BROWN: You know, you look in this documentary at a lot of issues and developments in treatments. One very intriguing thing was the role of exercise. Tell us a little bit about that.
DAVE IVERSON: Well, what people are starting to find is that exercise may play a real role both in protecting the brain, making it less likely that you might get Parkinson's, but also as importantly -- more importantly for someone like me -- it may really play a role in slowing the progression of the disease.
And there's lots of interesting research going on. One that we detail in the film has to do with animal research, where monkeys are trained to run on treadmills and the buff monkeys appear to do much better than the sedentary monkeys once they're given a low dose of a toxin that creates a Parkinson's-like condition.
They really continue to do very well after getting that toxic dose. Even their brains look different. Their production of a substance called dopamine, which is key, which is what goes missing in Parkinson's, remains almost the same.
So there's a lot of indicators right now that exercise may play a really important role for anyone who has Parkinson's.
Parkinson's is 'idiosyncratic'
JEFFREY BROWN: Dave, I want to ask you, because this is clearly such a fascinating mix of your professional interest and now personal concerns. Where do things stand for you personally, health-wise with the disease?
DAVE IVERSON: Well, I'm extraordinary fortunate in many, many things in my life, including my own situation with this condition. Parkinson's is very idiosyncratic. It proceeds one way with one person, another with someone else.
As Michael J. Fox likes to say, we each get our own customized version of the disease, but unfortunately none of them come with operating instructions.
But I'm really lucky. I'm doing very well. And I'm extraordinarily hopeful about the future. You know, we often talk about sort of winning or losing the battle with these diseases. And I don't know. I don't know, Jeff, when a cure will come.
But I do know you can fight the battle. I do know that there's enormous reason to be hopeful. And I'm myself extraordinarily hopeful about what the future will bring.
JEFFREY BROWN: All right, the "Frontline" documentary tonight is "My Father, My Brother, and Me." Dave Iverson, take good care, and thanks for talking with us.
DAVE IVERSON: Thank you, Jeff.