“Parents make crucial decisions for their children all the time – where children are educated, how they are raised, how they feed them,” says Mr. Rabinowitz of Natera. “In a way, this is not so different.”
But Dr. Kimmelman says there is a crucial distinction: “When you put your child in a private school, the child interacts with the [environment] he or she has a choice about how they interact with it …. But when you make a medical decision, it results in a biological cascade of events in which they have no choice.”
And despite all its advances, science still knows too little about how genes function. Some do more than one job – genes involved in sickle cell anemia, for instance, also play a role in protecting against malaria. Is it possible that the genes judged undesirable could come back to haunt us?
“The history of medicine,” Dr. Kimmelman notes, “is filled with unintended consequences.”
Preconception screening, or ‘offspring projections'
Dr. Handyside predicts that one day soon parents will know long before sperm meets egg what ills may befall their children. Studies estimate that unknowingly we all carry genes linked to three or more diseases – he recently discovered that his include cystic fibrosis.
“The 21st-century couple is going to say, ‘Right, we want to start a family,' and then they get a $1,000 gene test and see what ... they carry that might get passed on.”
In the U.S., the future has already arrived as companies have begun to offer preconception screening. Existence Genetics in California calls it “offspring projections,” and analyzes the entire genomes of two people “to determine which diseases and traits their offspring are likely to inherit.”
Company founder Brandon Colby says that, in a way, his genes determined his future. Growing up in Long Island, N.Y., he was never allowed to run or play field sports with the other boys.
“Why?” he asked his parents.
“Because of your genes,” they replied.
Born with epidermolysis bullosa simplex, an incurable genetic condition, he breaks out in painful blisters on his hands and feet when exposed to heat and friction. As a child, he had to be held down while they were lanced.
Now 33, Dr. Colby is a geneticist with a business degree from Stanford and a company with a microchip that can test a remarkable 1,500 genetic traits at once, including heart disease, seasonal affective disorder, obesity, athletic ability, hair and eye colour, height, susceptibility to alcohol and nicotine addictions, lactose intolerance and one of several genes linked to intelligence. This particular gene has been shown to result in a seven-point IQ gain if a baby is also breast-fed, he says: “We're interested in using the genetic information that will allow parents to take action.”
Still, a technical hurdle remains – figuring out how to amplify enough DNA from a single embryonic cell to run such an extensive test. But Dr. Colby is confident that the answer is coming soon, just as he is certain that “PGD will be part of my reproductive future.”
He is determined not to hand down his skin condition, even if he has thrived despite it – becoming a doctor, building a business and writing a book (called Outsmart Your Genes). He has even found a way to exercise – cruising the hillsides of Santa Barbara on a bicycle with custom-made, non-friction handlebars and special shoes.
“I have wrestled with this idea, that if this technology had been available to my parents, I might not be here. But then someone else would be and, hopefully, that person would have had the same value of a life.”
Of course, even erasing his own existence seems insignificant compared with his plans for shaping the future. Eventually, “we're going to see most [major]diseases fade from existence,” he says.
“Our next major leap of evolution as a species will be one that we control.”
Editor's note: The Center for Genetics and Society is based in California. Incorrect information appeared in an earlier version of this article.