Kim looked at every gene linked to Charcot-Marie-Tooth—there are more than 40 overall, each one imparting a slightly different character to the disease. One leapt out: LMNA, which codes for a group of rope-like proteins that mesh into a tangled network at the centre of our cells. This ‘nuclear lamina’ provides cells with structural support, and interacts with a bunch of other proteins to influence everything from the packaging and activation of genes to the suicide of damaged cells. Given this central role, it makes sense that mutations in LMNA are responsible for at least 15 different diseases, more than any other human gene. These laminopathies comprise a bafflingly diverse group—nerve disorders (like Charcot-Marie-Tooth), wasting diseases of fat and muscle, and even premature aging.
As Kim read about these conditions and their symptoms, she saw her entire medical history reflected back at her—the contracted muscles in her neck and back, her slightly misaligned hips and the abnormal curve in her spine. She saw her Charcot-Marie-Tooth disease.
She also saw a heart disorder linked to the LMNA gene that wasn’t ARVC but which doctors sometimes mistake for it. “Everything was encapsulated,” she says. “It was like an umbrella over all of my phenotypes. I thought: This has to be the unifying principle.”
* * *
Kim was convinced that she had found the cause of her two diseases, but the only way to know for sure was to get the DNA of her LMNA gene sequenced to see if she had a mutation. First, she had to convince scientists that she was right. She started with Grogan, presenting her with the findings of her research. Grogan was impressed, but pragmatic. Even if Kim was right, it would not change her fate. Her implant was keeping her heart problems under control, and her Charcot-Marie-Tooth disease was incurable. He didn’t see a point. But Kim did. “I wanted to know,” she says. “Even if you have a terrible prognosis, the act of knowing assuages anxiety. There’s a sense of empowerment.”
In November 2010 Kim presented her case to Ralitza Gavrilova, a medical geneticist at the Mayo Clinic. She got a frosty reception. Gavrilova told Kim that her odds of being right were slim. “I got this sense that she thought I’d made an unfounded shot in the dark,” says Kim. “That I didn’t understand the complexity of the genome. That I had been reading the internet, and they come up with all sorts of things there.”
Gavrilova pushed Kim towards a different test, which would look at seven genes linked to ARVC. Her insurance would cover that, but if she insisted on sequencing the DNA of her LMNA gene, she would have to foot a $3,000 bill herself. Why waste the money, when it was such an unlikely call? But Kim was insistent. She knew that the known ARVC genes explain only a minority of cases and that none of them was linked to neural problems. In all her searching she had found only one that covered both her heart and nervous problem. Eventually, Gavrilova relented.
Kim, meanwhile, disappeared down to Baja in Mexico. Gavrilova’s scepticism had worn her down and she fully expected that the results would come back negative.
When she returned home in May, there was a letter waiting for her. It was from Gavrilova. She had been trying to call for months. The test had come back positive: on one of her two copies of LMNA Goodsell had a mutation, in a part of the gene that almost never changes. LMNA consists of 57,517 DNA letters, and in the vast majority of people (and most chimps, monkeys, mice and fish) the 1,044th position is filled by a G (guanine). Kim had a T (thymine). “All evidence suggests that the mutation found in this patient might be disease-causing,” Gavrilova wrote in her report.
In other words, Kim was right.
“I’m beyond impressed,” says Michael Ackerman, a geneticist at the Mayo Clinic. He specializes in inherited heart disorders like ARVC that can cause sudden death at any time. Such diseases make for people who do their homework, but Ackerman describes most as “Google-and-go” patients who check their diagnosis online, or read up about treatment options. Kim had written up her research as a white paper—36 pages of research and analysis. “Kim’s the only one who handed me her own thesis,” he says. “Of all the 1,000-plus patients I’ve taken care of, none have done extensive detective work and told physicians which genetic test to order.”
He thinks she nailed it too. It is unlikely to be the whole story—Kim almost certainly has other mutations that are affecting the course of her disease—but LMNA “is certainly the leading contender for a unifying explanation, without there being a close second,” he says. “The evidence is pretty good for this being a smoking gun.”
The test had vindicated her hypothesis, but it also raised some confusing questions. Heart problems are a common feature of laminopathies, but those mutations had never been linked to ARVC, Kim’s specific heart malfunction. Had she been misdiagnosed? A few months later, Kim stumbled across a new paper by a team of British researchers who had studied 108 people with ARVC and found that four had LMNA mutations (and none of the standard ones). “To the best of our knowledge, this is the first report of ARVC caused by mutations in LMNA,” they wrote. They didn’t know about Kim’s work—they couldn’t have, of course. But she knew. Kim had beaten them to it. “I was so excited, I was running up and down the beach,” she says.