Surprise Daddies, Grim Diseases Lurke in Human Genome
Over the last ten years, the price of mapping the human genome has gone from $1 billion to less than $1,000 and will surely drop more.
Yet I have no wish to know what lurks inside the coils of my DNA, and neither does Robert Klitzman, a medical doctor who is professor of clinical psychiatry and the director of the Masters of Bioethics Program at Columbia University. He has not pondered his genome either.
Others may have little choice. They are ill already or at risk. Information will be a burden, or maybe not.
Klitzman talked to several dozen people confronting breast cancer, Huntington’s and alpha-1 antitrypsin deficiency (or “Alpha”), which affects liver and lungs.
Confusion, anger and regret infuse their stories as they unfold in Klitzman’s involving new book: “Am I My Genes? Confronting Fate and Family Secrets in an Age of Genetic Testing.”
We spoke at the New York world headquarters of Bloomberg News.
Hoelterhoff: Just getting tested so often involves great courage. What’s the worst you can discover?
Klitzman: That you have a mutation for Huntington’s. You will lose your mind and control of your body. And you will die.
Also, if parents and their offspring are tested, we will learn that a lot of people are not the children of the fathers they thought they were. Probably three to four percent.
Hoelterhoff: That’s a lot of stressful conversations!
Klitzman: Thousands, if you realize that increasing numbers of people are going to be tested in the coming years.
Hoelterhoff: Why is Huntington’s untreatable?
In the Brain
Klitzman: It’s in the brain, at the level of cells in the brain. We can’t cut it out.
It is hard to impinge on the brain. There are more synapses in the brain than there are cell phones in the world. Imagine you want to alter a billion conversations all over the world.
Hoelterhoff: Not everyone with breast cancer has the mutation. How does that happen?
Klitzman: Only 5 to 10 percent of breast cancer is the genetic kind, as far as we know.
Hoelterhoff: So not every disease has a genetic marker, a mutation that changes everything?
Klitzman: Right. For many diseases, like depression or diabetes, it’s a combination of genes, behavior and the environment.
And some diseases may be the result of several mutations. We used to look for one gene -- now we’re beginning to look at all of our DNA and will be learning a lot more.
Hoelterhoff: What does the human genome look like?
Klitzman: It consists of double spiral chains that contain four molecules that line up in different combinations to form three billion pairs.
So if this wall behind me were filled with 1,000 books, that would be about three billion letters. In that information are the instructions that make a human being.
There are about 1,000 typos in everyone’s genomes that basically don’t matter. For instance, we would still read “Amrica” as “America.” But “Car and Peace” completely changes the meaning and creates a functional problem.
Hoelterhoff: How close are we genetically to, say, chimps?
Klitzman: We share 98 percent with chimps, 90 percent with cats, 69 percent with rats and 60 percent with chickens.
Hoelterhoff: How did knowledge of their genetics affect the people you interviewed?
Klitzman: They had to make very difficult decisions -- whom to tell, and whether to have children, abort fetuses, screen embryos or adopt.
We can now screen embryos for hundreds of diseases. Some people with Huntington’s and breast cancer now decide to test embryos to make sure that these mutations are not passed to the next generation.
But that raises concerns, too. In the future, wealthy people will be able to afford eliminating various mutations from their descendants, while poor people won’t be able to do so. Many diseases may thus come to affect the poor, but not the rich.
Hoelterhoff: And it’s not just a matter of disease?
Klitzman: No. People are also choosing the gender of their children, and they will be able to “design babies” in other ways as well.
As soon as scientists identify markers associated with intelligence, blond hair, blue eyes or perfect pitch, parents will no doubt test embryos for these as well.
We are entering a Brave New World.
Hoelterhoff: Genetics inevitably brings to mind Drs. Mengele and Frankenstein. So could a mad scientist on an island with endless resources clone himself?
Klitzman: At some point soon, people probably could clone human beings. It will be feasible, though the U.S. and other governments have prohibited it.
Still, a mad scientist on an island or in a rogue country could potentially make multiple copies of himself and rent wombs in India for $3,000 apiece. He could make a little army.
Hoelterhoff: While some of the people in your book think getting tested will help them confront, say, Alpha at a time that might ameliorate the disease, others don’t want to know they just might be doomed.
Percolating through your book is the question -- and actually the fear -- of wider testing and storing DNA in bio banks because of the implications for insurance and privacy.
Klitzman: Suppose someone leaves DNA at a crime. Could law enforcement and the courts have access to the banks? Could you still plead the fifth, for instance? The government could say: “Tough, we have your DNA and are subpoenaing it.”
Hoelterhoff: Why didn’t you have your genome mapped?
Klitzman: I guess I like my life the way it is. I don’t want to complicate it.
And for a healthy person, I don’t think we are at a point where the medical information is actionable. I know there is heart disease in my family, so I watch my cholesterol.
Hoelterhoff: In one of my favorite films, Jeff Goldblum gets horribly mixed up with a house fly.
What are the chances of combo creatures? I’ve always yearned for a pet centaur.
Klitzman: We have made sheep that have partly human hearts. We’ve made pigs that produce human blood, and glow-in-the-dark fish that detect toxins in the water.
But to combine major body parts of species genetically -- to add wings to people -- would be very complicated now.
(Manuela Hoelterhoff is executive editor of Muse, the arts and culture section of Bloomberg News. The opinions expressed are her own.)
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