In 2010, Sonia Vallabh watched her mom, Kamni Vallabh, die in a really horrible way.
First, her mom’s memory started to go, then she lost the ability to reason. Sonia says it was like watching someone get unplugged from the world. By the end, it was as if she was stuck between being awake and asleep. She was confused and uncomfortable all the time.
“Even when awake, was she fully or was she really? And when asleep, was she really asleep?” says Sonia.
The smart, warm, artistic Kamni – just 51 years old — was disappearing into profound dementia.
“I think until you’ve seen it, it’s hard to actually imagine what it is for a person to be alive and their body is moving around, but their brain is not there anymore,” says Eric Minikel, Sonia’s husband.
In less than a year, Sonia’s mom died.
An autopsy showed Kamni had died from something rare — a prion disease. Specifically, one called fatal familial insomnia because in some patients it steals the ability to fall asleep.
Basically, certain molecules had started clumping together in Kamni’s brain, killing her brain cells. It was all because of one tiny error in her DNA — an “A” where there was supposed to be a “G,” a single typo in a manuscript of 6 billion letters.
Sonia sent a sample of her own blood to a lab, where a test confirmed she inherited the same mutation. The finding threw the family into grief all over again.
Today, Sonia and her husband live and work in Cambridge, Mass., where they are both doctoral students in the lab of Stuart Schreiber, a Harvard professor of chemistry and chemical biology. Over the past several years, the couple has completely redirected their careers and their lives toward this single goal: to prevent prion disease from ever making Sonia sick.
Photos: Kayana Szymczak for NPR