DAVID GREENE, HOST:
Today, in Your Health, the story of a mysterious disease that took one woman's life and is now threatening another. This story starts eight years ago at a wedding in Pennsylvania. NPR's Rae Ellen Bichell reports.
RAE ELLEN BICHELL, BYLINE: When Sonia Vallabh and Eric Minikel got engaged, they decided they wanted a small ceremony, something in the backyard. Sonia told her parents, who grew up in India, about their plans.
SONIA VALLABH: I said, like, you know, we'd love to have a small backyard wedding. And my parents said, oh, we heard you say you'd love to have a huge Indian wedding. And I was like, oh, no, actually (laughter).
BICHELL: Sonia's mom Kamni Vallabh made it work for everyone quietly and humbly.
VALLABH: Yeah, that's right. She wasn't like a spotlight person.
BICHELL: They ended up with a sizable Hindu wedding, distilling a multi-day ceremony down to about an hour. There were garlands of roses, a stage.
VALLABH: And we got to read some of these, like, hilariously formal, antiquated translations from Sanskrit.
(SOUNDBITE OF ARCHIVED RECORDING)
ERIC MINIKEL: (Speaking Sanskrit), my blessed bride, I now decorate you with this sacred necklace. May you prosper with me for hundreds of years. (Singing in foreign language).
It was fantastic.
MINIKEL: It was such an amazing event.
MINIKEL: Happiest day of my life.
BICHELL: In the wedding video, Sonia's mom Kamni never speaks, but there she is, sitting off to the side in the sky-blue sari. What nobody knew that day was that, deep down, her body was changing. It took a few months for people to notice the symptoms - blurry vision, weight loss, memory problems. It wasn't clear how big of a deal this illness was.
VALLABH: But that changed very quickly. So if that was the story in February, by March, I was talking to her on the phone, and her speech and her sort of lucidity had just totally deteriorated to the point where she couldn't get from the beginning to the end of a sentence. And at this point, people were starting to get scared.
BICHELL: Kamni Vallabh's mind started playing tricks on her, like the time she lost the remote control and was convinced she'd find it in the kitchen pantry.
VALLABH: She was seen by a bunch of neurologists, and a bunch of tests were done.
BICHELL: No positive results. Her memory and reasoning were getting worse.
VALLABH: And the number of incidental complications was continuing to pile up. She had aspirational pneumonia twice. She went into the ICU a couple times incidental to the search for a diagnosis, which was ongoing and still not fruitful. And by summer, she was in the hospital in a series of hospital stays that basically lasted the rest of her life.
BICHELL: Kamni was only 52 years old. She couldn't talk anymore, and she had to go on life support. Her will said she didn't want to be kept alive with the terminal diagnosis, but there still wasn't a diagnosis.
VALLABH: Without a name for the disease, people disagreed about whether what we were seeing was clear evidence that she had a deadly disease or whether it was sort of a state from which she might emerge.
BICHELL: But the months kept passing - still no diagnosis. By fall, it was really bad. Eric, her son-in-law, says nurses had to chain her hands to the bed so that, in her confusion, she wouldn't pull out all the tubes keeping her alive.
MINIKEL: It was really, really grim. It was a way that we should never treat a human being.
BICHELL: Eventually, it became clear she wasn't going to get better, and the Vallabhs took her off life support. After she died, they ordered an autopsy, and it confirmed what doctors had suspected. The thing that killed Kamni Vallabh is something that we all have inside us, something called prion proteins - squiggly molecules that sit on the outside of our brain cells.
People don't really know why we have those proteins, but they're no problem unless, in very rare cases like Kamni's, one of those proteins folds into the wrong shape. Some of its squiggles flatten out a little. And when that happens, things go very wrong.
ERIC LANDER: Prion diseases are so bizarre.
BICHELL: That's Eric Lander, a mathematician and geneticist who founded the Broad Institute of MIT and Harvard.
LANDER: What happens is you produce a protein that misfolds. And that protein causes other proteins to misfold.
BICHELL: As more and more proteins misfold, neurons start to die. It's like a virus spreading through the brain, except it's not a virus. It's as if an infection has come from inside your own body.
LANDER: It's caused by one of your own proteins that subverts other proteins in the brain. It's a really bizarre mechanism.
BICHELL: Scientists tend to avoid comparing illnesses to people. But in this case, researchers liken protein folding to the transformation of Dr. Jekyll to Mr. Hyde, the infamous character with two sides - one good and one evil.
(SOUNDBITE OF FILM, "DR. JEKYLL AND MR. HYDE")
SPENCER TRACY: (As Dr. Jekyll/Mr. Hyde) Can this be evil then (laughter)?
PETER GODFREY: (As Poole) Dr. Jekyll, who is that in there?
BICHELL: The prion protein in Kamni's brain had become the bad shape, the Mr.-Hyde shape, and convinced all the others around it to do the same. They spread and spread, killing off Sonia's mom's brain cells.
VALLABH: So I think that process was beginning in January, February 2010.
BICHELL: There are a few different forms of prion disease. But the one that took Kamni is called fatal familial insomnia because in some patients, it steals the ability to fall asleep. It had all happened because of a single typo in Kamni's DNA.
VALLABH: It's just one letter in this relatively small gene.
BICHELL: An A where there's supposed to be a G, a single typo in a manuscript of six billion letters. And Sonia had a 50/50 chance of having the same typo. She sent a blood sample to a lab to see if she did. It took months to hear back.
VALLABH: I think 50/50 is, like, an inherently hard thing to think about. Even if you're not a superstitious person, like, your mind plays tricks on you because what can you do with, like, perfectly even odds?
BICHELL: Finally, the results came back positive. She had it. According to current research, that means Sonia will very probably die the same horrible death as her mom.
VALLABH: It's an incredibly bleak picture.
BICHELL: But Sonia and Eric aren't ones to accept things the way they are. They're the kind of people who play complicated board games for fun, the kind of people who will go to graduate school in law and urban planning so they can defuse conflicts and fix cities. They're problem-solvers. And this was something they had to solve. So they decided to become scientists. I'll tell you how they did it this afternoon on All Things Considered. Rae Ellen Bichell, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.