The same genetic mutation leads to dramatically different results.

David Epstein wrote a book about the intersection of genetics and sports and that put him in contact with a lot a of crazy people. He stopped looking at inquiries until he noticed the subject heading of one message reading, “Olympic medalist and muscular dystrophy patient with the same mutation.” That interested him and it put him contact with an impressive woman named Jill who diagnosed her own rare condition, collected information about it, and eventually contacted Italian researchers looking into her specific and very rare genetic mutation.

Through her research into her family she was able to warn her father of the hazards of his own condition that he passed onto her and her sibs stirring him to look into something he had ignored. Her warning prolonged her father's life by decades.

During a holiday gathering Jill's sister was researching her own related genetic condition and noticed a photograph of an olympic runner showing the same lack of fat around certain muscles while running that seemed odd and showed it to Jill's who made the connection to her own condition by her advanced eye. Jill was shown one picture of the athlete and became obsessed. She looked at more pictures of Pricilla the athlete in Google images of her doing ordinary things. She saw the same effects on the athlete's well-muscled body that she sees in her own deteriorating body. She contacted the athlete. They agreed to meet.

Jill and Priscilla spoke on the phone several times. Then, eight months after I introduced them, they agreed to meet in person. They picked a hotel lobby in Toronto, where Priscilla lived. Jill arrived first, with her mom. 

She watched the clock. It ticked past the time they were supposed to meet. Jill got scared. This was a crazy thing she was doing. What if Priscilla had decided not to show? She watched the door. And when Priscilla walked in, Jill’s first thought was “Oh my gosh, it’s like seeing family.” 

Priscilla felt the same way.  “It really was just a wow moment,” Priscilla says. “Like, do I know you?” The two women started flexing for one another. Priscilla’s muscles many times larger, but with the same definition exposed by a lack of fat. They even retreated to a hallway in the hotel to compare body parts. “There is something real here,” Priscilla recalls thinking. “Let’s research. Let’s find out. Because how could the gene do this to you and this to me? That was what my question was. How?” 

Jill offered Priscilla a cashier’s check, money that had been raised for research in a memorial fund after her father’s death. Jill hoped Priscilla would take it and use it to pay for a genetic test. And Priscilla agreed.

Turns out they do share the same mutation. Pricilla had been subjected to intense scrutiny due to suspicion of using enhancing drugs. Due to Jill's correctly suspecting Pricilla's condition Pricilla was alerted to elevated triglyceride level in her bloodstream that would have  killed her.

Propublica.