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Are we destined to live in a world of “previvors” and “post-humans”?


Hollywood has already imagined it: Gattaca, an apocalyptic world driven by genetic engineering, where only embryos with the best of their parents’ characteristics (“valids”) become children.

That was 1997, a few years before the Human Genome Project released its first draft, and 15 years before the Crispr-Cas9 genome editing technique transformed genetic mapping, making it exponentially quicker and less expensive.

Now, author and physician Siddartha Mukherjee, M.D., warns, Gattaca doesn’t seem so far-fetched.

“Technology has advanced so quickly, we can predict what will happen in the future,” he said at the University of Utah’s Tanner Lecture on Human Values Tuesday. Scientists are doing more than simply reading and copy editing the human genome, Mukherjee says. They’re starting to write it.

Mukherjee, assistant professor of medicine at Columbia University’s College of Physicians and Surgeons and author of the Pulitzer Prize-winning Emperor of All Maladies: A Biography of Cancer, uses genetics-based precision medicine to treat leukemia patients at his New York clinic. But he also points out the limits of so-called “big data” – massive genome mapping projects that generate huge amounts of information which may or may not provide insight into treating individual patients’ tumors.

Mukherjee is not the first doctor to sound an alarm about the transformative power of willy-nilly genetic editing. But he also dissects the previously positive definition of “previvor”-ship popular among those diagnosed with genetic predispositions for cancer. “Previvors” celebrate being spared by preventive treatments and surgeries. But Mukherjee worries manipulating human genetics with the goal of making people healthier might one day veer into something more dangerous.

When does genotyping of embryos–curtailing everything from fatal genetic mutations to aesthetic characteristics like the propensity for brown hair or a big nose – end up also eliminating the serendipity of human variation? Will we have to redefine what it means to be “naturally” human? When do hyper-genotyped babies become “post-humans?”

And in the meantime, what happens to society as more and more people become “previvors,” he wonders, living with detailed knowledge of a personal genome riddled with potentially deadly anomalies? How will that knowledge change us?

Simply having the BRCA1 gene does not guarantee a person will develop breast cancer, he notes. But those with the gene might live their lives always anticipating the fateful biopsy–or end the waiting with a prophylactic mastectomy.

Gene editing inspires wonder, he says, but also moral queasiness. Individual genetic screening advances might not be alarming, but considered together, they reveal the broader impact of rejiggering the human genome.

“Illness might progressively vanish, but so might identity,” he said. “Grief might diminish, but so might tenderness. Traumas might be erased, but so might history. Mutations might be eliminated, but so might variations. Chance would become mitigated, but inevitably, so might choice.

“There are important consequences on the psyche, on the culture,” he added. “We have to be very careful about that so that we don’t contaminate our culture so that everyone is living in anticipation of a disease they haven’t had yet.”

Mukherjee is afraid scientists will jump too quickly into “genetic management.” He traces a line from the eugenics movement of the late 1800s, to Adolf Hitler’s campaign to “cleanse” Europe of undesirables in the 1930s and 1940s, then to Watson, Crick and Franklin’s double helix. Genetic screening has become a politically and socially palatable way to manage naturally occurring, but uncomfortable, human diseases. And well-meaning doctors intent on saving their patients the suffering of genetically linked death sentences, including cystic fibrosis and Huntington’s, he says, eventually could veer into manipulating human genomes to eliminate obesity, acne, depression or early-onset baldness.

Last year, Chinese scientists were criticized for manipulating “non-viable” human embryos to block a potentially fatal blood disorder, setting off a firestorm of criticism. But Mukherjee figures it’s only a matter of time before Western researchers follow suit.

“The first ‘post-human’ may be on his way to being born,” he said. 

By: Rebecca Walsh

Rebecca Walsh is a Senior Writer for University of Utah Health Sciences.