Thursday, January 27, 2011
The disease would have been terrible enough for an adult, but in 3-year-old Nicholas Volker, it was almost fatal. The Wisconsin toddler had undergone more than 100 surgeries in an attempt to cure a progressive, inflammatory bowel condition that caused holes to open between his intestines and his skin whenever he ate.
Surgeons ultimately removed his colon. But he kept getting sicker.
Then doctors took the extraordinary step of mapping 1 percent of Nicholas’ genome, that most detailed set of biological blueprints that controls everything about a person from the color of their eyes to the possibility that one day their heartbeat will go awry because of a genetic abnormality. They found in Nicholas a genetic mutation so rare that traditional methods never would have detected it.
He received a transplantation of cord blood in 2010 to treat the disorder, and while his health is still fragile, he’s eating solid food and living life like an almost normal 6-year-old boy.
What science did for Nicholas has its origins in the Human Genome Project, the $3 billion, 13-year U.S. government project to map all of the nearly 25,000 genes in human DNA. The project has led to explosive growth in a sector called “personalized medicine,” the analysis of an individual’s genes to detect variations and discover risk factors for certain diseases.
In the eight years since the Human Genome Project, hospitals have begun more thoroughly investigating how patients can benefit from personalized medicine, and companies have cropped up to bring testing straight to the consumer. An hour or so up Highway 101, Mountain View’s El Camino Hospital launched a Genomic Medicine Institute offering 2,000 genetic tests; it’s the only such community hospital institute in California and one of only five in the country.
Closer to home and for the low price of $199, a consumer can order up a test from 23andMe Inc. Spit into a tube, mail it to the labs and the California company promises a two-month turnaround on reading 1 million of a customer’s 10 million SNPs (that’s single nucleotide polymorphisms), the small genetic changes that can occur in a DNA sequence.
The saliva sample can reveal ancestral origins, predicted responses to drugs, and the genetic predisposition of getting upwards of 95 diseases, from diabetes to Parkinson’s to Alzheimer’s.
Nicholas Volker’s case is one of the first documented in which such large-scale genetic analysis led to an effective treatment. On a smaller scale, though, gene analysis is routine at Monterey County hospitals in the area of perinatal care.
“We’re using those same techniques for other things, for prenatal diagnosis, and in helping women understand their own disorders related to potential fetal disorders,” says physician Amen Ness, head of the Stanford University-affiliated Perinatal Diagnostic Center at Salinas Valley Memorial.
“In a family, if there’s a genetic disorder already identified, then we can offer testing or sequencing of the fetal genes to look and see if the baby carries the same thing.”
For example, testing a mother’s Rh factor, a protein on the surface of red blood cells, is a routine test done on all pregnant women. If a mother doesn’t carry an Rh factor and the fetus does, the mother’s antibodies can attack a fetus’ blood cells and lead to death.
But it takes an analysis of the father’s blood type and genes to know if the baby’s Rh type is different. “It changes the whole management of the pregnancy,” Ness says. Other somewhat routine genetic tests at the hospital include those for cystic fibrosis, a disease resulting from abnormal genes in both parents.
Genetic testing also can be a tricky business, with labs chosen carefully for their expertise in certain genes and insurance companies that need coddling over whether a test is covered or not. “Some of these tests can cost thousands of dollars,” Ness says. “In most cases we can get it done if the patient wants it… but a lot of these tests are just hints. The technology sounds like ‘Just do it,’ but there’s a lot of subtlety to it.
“It has to be something that matters. It has to be something you can do something about.”
Researchers believe the eventual possibilities for genomic medicine are endless. One possibility: an over-the-counter pain reliever so targeted to the DNA blueprint that it would take only one-thousandth of a tablet to make a headache disappear.
Paul Billings, a physician, entrepreneur and internationally recognized expert on genetics, writes extensively on the ethics of genetic testing. Now medical director at the biotech firm Life Technologies Inc., he says that mapping an individual’s entire genome eventually will cost no more than dinner for two at a nice restaurant.
Right now, though, what exists is the potential to access a lot of information about one’s genes without necessarily being able to do something about it.
“We’re seeing an explosion of information with no beginning of clinical discussion or what to do about it,” he says. “Some of that information may be important to research, but some of it just isn’t clinically useful at this point.”
Like knowing if genes predispose a patient to Alzheimer’s. Having the gene variation doesn’t mean they’ll get the disease – it just means they might.
“If you ask 100 people, 60 percent say there’s little value in knowing, 20 percent say adamantly they don’t want to know,” Billings says. “But the other 40 percent say they will take better care of themselves and plan to reduce burdens on their families. Those are respectable reasons for knowing.”
Billings says he had his genome mapped and found it “mostly useless.”
“I was intensely ambivalent, but that’s my stance on life and my overall psychology,” he says. “I was certainly curious, but I was worried I would find something out that I didn’t like and couldn’t do anything about. Happily, I didn’t have that experience.”
Learn more at www.23andme.com. For serious medical advice on genomics, consult your local physician or visit El Camino Hospital’s Genomic Medicine Institute at www.elcaminohospital.org/Genomic_Medicine_Institute.