The scientists, arriving by boat, found patients everywhere, some of them children, with the classic writhing and flailing signs of the disease, which was known locally as “el mal.”
Dr. Wexler told them that she and they were related, that her family had the disease, too. She showed them a tiny scar on her arm where she’d had a skin sample taken, as she was asking them to do.
“I fell in love with them,” she said.
For 20 years, she returned with teams that ultimately collected 4,000 blood samples. They traced the path of the disease through 10 generations in a family tree that included more than 18,000 people.
“Working with Nancy in Venezuela was a real testament to how an individual can take a team and get absolutely water out of a brick,” said Dr. Anne B. Young, a professor and former chief of neurology at the Massachusetts General Hospital, who made 22 trips to Venezuela with Dr. Wexler. “She was able to take all of us and drive us, 16 hour days out in the field where it was 96 degrees and 90 percent humidity.”
Dr. Wexler was a powerful presence.
“She was just totally charismatic, and when you walked into the room she would hug you and look you in the eye and listen to everything you said,” Dr. Young said. “She never thought about herself. She was always thinking about what she could learn from the other person. People just became totally devoted to her. Everybody felt they’d take a bullet for her.”
In 1983, just four years after the first trip, the team found a marker, a stretch of DNA that was not the gene itself but nearby. It took a half dozen high-powered research groups — handpicked by Dr. Wexler and her father — 10 more years to find the gene itself, on chromosome 4, one of the 23 pairs of chromosomes found in most cells in the body.
The discovery was a landmark in genetics, one that scientists say would never have happened without Dr. Wexler.