I watched as scientists, ethicists, patient advocacy groups and others wrestled with these topics at the Third International Human Genome Editing Summit in London earlier this week.
There’s a lot to be excited about when it comes to gene editing. In the decade since scientists discovered they could use CRISPR to edit the genomes of cells, many clinical trials have been conducted to test the technology’s use in serious diseases. CRISPR has already been used to save some lives and change others.
But not everything was smooth. Not all tests went according to plan, and some volunteers died. Successful treatments are likely to be expensive and thus limited to the wealthy few. And while these tests typically involve making changes to genes in adult body cells, some hope to use CRISPR and other tools to edit genes in eggs, sperm and embryos. The specter of designer kids continues to loom over the field.
At the most recent summit held in Hong Kong in 2018, He Jiankui, then at the Southern University of Science and Technology in Shenzhen, China, announced that he had used CRISPR on human embryos. The news of the first “CRISPR babies,” as they have come to be known, caused a massive uproar, as you can imagine. “We will never forget the shock,” Victor Dzau, president of the US National Academy of Medicine, told us.
He Jiankui ended up in prison and was released only last year. And while hereditary genome editing was already banned in China at the time – it had been banned since 2003 – the country has since passed a series of additional laws aimed at making sure nothing like it happens again. “Today, heritable genome editing is prohibited by criminal law,” Yaojing Peng of the Beijing Institute of Stem Cell and Regenerative Medicine told the audience.
There was much less drama at this year’s summit. But there were many emotions. In a session on how gene editing could be used to treat sickle cell disease, Victoria Gray, a 37-year-old survivor of the disease, took to the stage. She told the audience how her severe symptoms disrupted her childhood and adolescence and dashed her dreams of becoming a doctor. She described episodes of severe pain that kept her hospitalized for several months. Her children were afraid that she might die.
But then she underwent treatment that involved editing genes in her bone marrow cells. Her new “super cells,” as she calls them, have changed her life. She told us that within minutes of the transfusion of the edited cells, she felt reborn and shed tears of joy. It took her seven or eight months to feel better, but after that, “I really started to enjoy the life that had once passed me by,” she said. I saw the ordinary stoic scholars around me wiping tears from their eyes.
Victoria is one of more than 200 people treated with CRISPR-based therapy in clinical trials, said David Liu of the Broad Institute of MIT and Harvard, who led the development of new and improved forms of CRISPR. Trials are also underway for a number of other conditions, including cancer, genetic vision loss and amyloidosis.
