A.From cancer to Alzheimer's ( 早老性痴呆病 ) to diabetes, advances in genetic sciencemean that many of us are soon going to know--or at least have the option to know--more about our risks for a wide range of illnesses than we'd ever thought possible.On the surface, that sounds like a good thing, and it is in many respects. But whileknowledge may be power, genetic testing also brings with it tremendous physical andpsychological collapse.
B.In the past two decades, the number of genetic tests available has jumped from a fewhundred to nearly 3,000. Rebecca Nagy, president of the National Society of GeneticCounselors (NSGC), recalls that when she entered the field 15 years ago, it took ayear to get the results of a BRCA ( 乳癌) test. Today, you get them back in a week ortwo.
C.As the cost of testing declines, says Lawrence Brody, an investigator with the NationalInstitutes of Human Genome ( 基因组) Research Institute. Medicine is movingtoward "multiplex testing for lots of things at once". We're at the point, he explains,where sequencing a person's entire exome 外显子组) can be done for somewherein the neighborhood of $1,000." Whereas before it would have been really bizarre tohave someone's entire genome sequenced because it cost about the same as the GDPof several small countries. With exome sequencing, a patient may go in with questionsabout his prostate ( 前列腺 ) and come out with a report showing increased risks foreverything from bloodclots ( 凝块 ) to kidney disease.
D. Such data points are known as "incidental findings", and they are at the heart of thehottest ethical debate now prevailing in the field, says Nagy. "What results do youdisclose to someone and what results do you withhold? And do you give patients
that choice?" One commonly cited example: what happens when a toddler'sexome is sequenced to determine the cause of a developmental delay and the labdiscovers that the child has the BRCA1 mutation ( 变异 ) ? Should the lab withholdthat information?
E. Nagy explains that "a basic principle of genetics is that patients should haveautonomy"--meaning the right to choose what they do and do not want to know.But the American College of Medical Genetics and Genomics issued a statementcontending that, in the case of certain specific harmful and active genes, doctors havean ethical obligation to alert patients to the discovered risks. Balancing this "duty towarn" with an individual's right to autonomy is tricky enough on its own. But thereare other complicating factors to consider. What if disorders are likely to impact otherfamily members? And what about all the mutations that will pop up but that we don'tyet understand? "The menu is probably more vast in terms of what you can look atthan people are prepared for, and the results will contain more uncertainty than peopleare prepared for."
F.Social worker Katie Berry has a front-row view of all the issues that this new medicallandscape is raising. Through Columbia Presbyterian Hospital in New York, Berrycounsels men and women at high risk for Huntington's ( 亨廷顿症) , an inherited
neurodegenerative disorder ( 退行性神经紊乱 ) that typically appears in midlifewith some brutal combination of physical, cognitive, and psychiatric decline. A personwith the Huntington's gene can expect to get sick at some point down the road. Thereis no cure and, unlike with breast cancer, no preventive measures beyond maximizinggeneral health with the aim of delaying onset.
G. Berry works solely with individuals not yet experiencing symptoms. Some havealready been gene-tested. Others know that the disease runs in their family andare hesitating about whether to get tested--and when. With no preventive optionsavailable for Huntington's, the question of when to test is often dictated by loomingdecisions about marriage or parenthood. Most of the patients who come to Berry arein their 30s or early 40s. "People who are in their teens and early 20s tend not to bethinking about these things," she explains. "There's a level of denial in very youngadults."
H. But as people start pairing up and settling down, the stakes of not knowing get higher.(People with the Huntington's gene have a 50 percent chance of passing it to a child.)"They know there is this sword of Damocles hanging over their heads," says Berry.But until the test is done, they can cling to the hope that they escaped the geneticbullet. "They think, 'It's possible I'll never get it. It's possible I can continue to livethe life I'm living now,'" she says. "Knowing creates a whole other reality--a hugelydifferent reality."
I.Indeed, the news that one's genome contains a potential time bomb presentsnumerous, extremely painful psychological hurdles. Breaking the news to family canbe a particularly rough part of the process, and not simply because of the heartbreakit brings loved ones. Learning that a family member has a particular mutation can suddenly force brothers and sisters, children and parents to confront unsettling questions about their own genes--questions that many people would prefer not tohave raised at all.
J. To facilitate sharing, medical facilities are increasingly providing aid and guidance. Visvanathan's clinic invites patients to have family come in and talk with the staff. "Wetry to take some of that burden," she explains. Hospitals at places like GeorgetownUniversity and the University of Pennsylvania often provide patients with lettertemplates tailored specifically toward informing family.
K. Then there's the long-term challenge of living with a genetic ghost hiding in thebackground. At times, the anxiety can cause great damage, says Berry. "People talkfrequently about how they go through periods--and I suspect it's true of anyone whofaces a chronic illness or potentially fatal disease--periods that last days, weeks,months, or even years when there's a hyper-alertness about the body." Every twitch,twinge, or tickle spurs a raw terror that the illness has begun to take hold. "Peoplesay they're convinced they have the disease even though there's nothing obviouslysymptomatic about them," Berry says.
L. For the medical community, addressing these challenges will mean changing medical-school curricula and investing in continuing education. "It means us going out tophysicians' offices and helping them understand when it's appropriate to refer aperson to a genetic counselor," Nagy says. "It's making them feel comfortable that,once referred, their patients will come back to them for ongoing care."
M.Much more broadly, the general public is increasingly going to need a grasp ofgenetic basics to better manage their health, says Visvanathan. "Maybe the geneticaspects of health need to be brought into schools," she says. "Informing people at ayoung age would be helpful." Where and when this education should take place is,in fact, already under discussion. "I was at a conference last year in Boston wherepeople were talking about how to educate elementary school kids," Nagy recalls.
N. Equally important, there will be a need for more organizations to do the simple workof linking those facing similarly cloudy futures to one another. Having a supportnetwork of others who understand the fears, thoughts, medical peculiarities, andeven the language of your disorder makes a huge difference, says Berry. "You see apositive effect when people realize that they are not journeying alone." In some cases,just having a regular chance to vent provides a measure of relief. "We have heardfrom patients that they love the support group because it allows them to gather all thatnegative energy, worry, and anxiety and spew it out in a one- or two-hour period," shesays. "Then the rest of the month they don't have to think about it so much." But theanxiety never fades entirely, says Berry. "It's always present, always niggling."
O.Such is the burden of knowledge--and, more specifically, foreknowledge. It is aburden more and more of us are going to have to decide whether to assume and onethat our medical system is just beginning to learn how to help us shoulder. "Thisreally is a slightly different pattern for medicine," says Brody. "It's going to take a lotof work."