Right now, a doctor can order up a genetic scan for a patient at a cost of $7,000 and get back a report about the unique set of mutations inside that person’s body. These aren’t the mail-order genetic tests from companies like 23andMe, which give consumers very limited results about their ancestry and possible health risks. These are medical-grade genome scans, which can provide precise information about genetic diseases people are actually suffering from or are at risk of developing.
This price point is nothing short of remarkable. When the federally funded Human Genome Project finished sequencing the first complete human genome in 2003, the total cost came to about $3 billion.
I got my own DNA scanned for an article I wrote about the plunging price of genome sequencing and the technological breakthroughs enabling the dramatic decline in costs. A commercial lab at Houston’s Baylor College of Medicine charged me $7,000 for both the scan and a detailed analysis, though they technically only looked at my exome — that is, the portions of my genome that contain genes. Those are the parts doctors have the best chance of interpreting.
I embarked on this genetic adventure because I wanted to see if these scans were predictive enough to be useful for someone like me, a healthy person in my mid-30s. If the results could provide clear forecasts for diseases I might develop later in life, I could adopt strict screening regimens to catch the first symptoms or make diet and lifestyle changes.
Such actions are commonly cited when researchers talk about genetic medicine’s potential to improve routine medical care and to bring down health care costs. By allowing patients to switch to a more preventative and less reactive model of medicine, the argument goes, we can reduce emergency visits and hospital stays and save money in the long run. So, did my experience support this argument?
Not really. My results showed genetic predispositions to heart disease, kidney failure, and Parkinson’s, but the markers were rough risk factors, not sure things. The scan showed that I had mutations in certain genes that have been associated with these diseases, but my particular mutations haven’t been proven to cause any problems whatsoever. The doctors said to weigh my results against my family medical history; I told them there’s no known Parkinson’s in the family, but a few family members have had heart and kidney problems. So, essentially, I can look out for heart or kidney symptoms or consider heart or kidney function tests when I get older.
But an overzealous testing regimen raises a new set of problems. If genome scans encourage healthy people to request complicated medical tests they do not really need, the potential economic benefits of genetic medicine could evaporate.
Still, a few classes of patients can already benefit enormously from comprehensive genome scans. Baylor’s Whole Genome Laboratory mostly provides scans for patients on “diagnostic odysseys,” having undergone tests of specific, suspect genes that failed to turn up any mutations – or a diagnosis, Genome Laboratory Director Christine Eng explained.
“They may have had thousands or tens of thousands of dollars of genetic testing previously,” she said, “And probably several rounds of frustration.”
With its more comprehensive genetic scans, the Baylor lab’s current diagnostic success rate is nearly 30 percent, meaning the lab can tell patients what specific mutations are causing their symptoms nearly one-third of the time. In the best cases, those diagnoses can improve treatments. In the worst cases, they can give patients and their families a clearer picture of their medical fate and allow for more definitive care and end-of-life plans.
Comprehensive genome scans are also starting to make sense in routine care for cancer patients. Some pioneering clinics and hospitals have begun to order genome scans of patients’ tumors, so they can study the exact mutations that are stimulating those cells to grow out of control. In a few trailblazing cases, the tests have shown doctors how to tailor their treatments to better attack a specific patient’s cancer.
“If you give just one person the right cancer treatment, you can save $20,000,” Jonathan Rothberg told me. He invented the top-of-the-line sequencing machine used in my DNA scan, and his company, Ion Torrent, was bought by the biotech giant Life Technologies Corp. in 2010 for $725 million. He thinks that cancer care will be the first “killer app” for genome sequencing technology, but that the progress will only continue.
“I do see sequencing becoming a routine part of medicine over the next few years, first as part of cancer diagnostics and therapy, and then later as more general medical test,” he said. “So in the same way that you’ll have an x-ray, you’ll have your genome sequenced.”
Rothberg is more bullish than I am on the promise of genome scans for routine medical care. But if the technology proves beneficial for the first sets of patients, both in terms of economics and medical outcome, doctors may eventually start finding real benefits for the rest of us as well.
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