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?