Researchers at Washington University's McDonnell Genome Institute in St. Louis will expand their work into common illnesses like Type 1 diabetes, stroke and arthritis, thanks to a $60 million federal grant.
To do that, they will examine patients' genetic make-ups to find slight differences in their DNA, which is made of a complex sequence of nitrogen bases: adenine, thymine, guanine and cytosine.
Depending on how those bases are ordered, a person might end up with green eyes, curly hair or rather large feet. But more importantly, genes control what’s going on inside the body. Deciphering those chemical codes can help tease out a person’s risk for specific illnesses and better ways to treat them.
It's a method typically used for cancer, but now the National Institutes of Health has granted a total of $240 million to four universities to apply the approach to more common illnesses like autism and heart disease.
“If you think about heart disease right now, there are really only two preventative drugs. One is aspirin and the other is statins,” said genomicist Rick Wilson, the grant’s principal investigator in St. Louis.
The genetic risks behind heart disease still aren’t well understood, Wilson said. The condition kills about 600,000 Americans a year, according to the Centers for Disease Control and Prevention.
“The idea is to see if we can’t find some genes to: A - allow us to assess risk a little bit better in people, and B - develop some new drugs,” Wilson said. “Not so much like a heart attack vaccine, but like a super-smart aspirin.”
Learning from cancer
In contrast, more institutional knowledge about cancer exists, related to the interplay between genes and the risk of developing certain types. The idea of swabbing one’s cheek to be analyzed has made its way into popular culture, including Angelina Jolie’s public decision to have a double mastectomy after discovering she had a gene that sharply increases the chance of developing breast or ovarian cancer. In a 2005 episode of Grey’s Anatomy, a patient elects to have surgery to remove her breasts and uterus after discovering she carries the same gene.
By studying the genomes of individual tumors, researchers realized many are so genetically similar they can be treated with the same drugs, even if they appear as different types of cancer in different parts of the body.
When it comes to cancer, researchers have the advantage of comparing the genetics of a patient’s healthy cells to that of the tumor itself. But the genomic sources of illnesses like heart disease, where lifestyle choices also contribute to risk, are much harder to isolate because the genomes of unrelated people have to be compared.
Scaling up
To meet this challenge, the project is designed at an enormous scale: the four universities will be tasked with mapping the genomes of 150,000 to 200,000 individuals from all over the world. According to Wilson, samples to be sequenced in St. Louis include residents of an isolated village in Finland and large numbers of African Americans, who have a higher risk for heart disease and stroke.
“What drives our ability to do this kind of audacious scale now is the technological advances that we have seen in DNA sequencing… that are inching us closer to the $1,000 human genome threshold,” said Dr. Eric Green, the Director of the National Human Genome Research Institute at NIH.
The first human genome ever sequenced cost $2.7 billion (in 1991 dollars) and took a little over a decade to complete. Today, researchers can sequence a genome in about a month, and it costs significantly less.
“With that kind of a price tag, it means that studies that were once unimaginable because of their scale are now quite possible,” Green said.
The four-year project's grants come with the caveat that they will be distributed “pending available funds” from the NIH budget, which is authorized by Congress.
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