Changing our DNA: The age of human therapeutic gene editing is here
(CNN)When popular YouTube star Adalia Rose died earlier this year, she looked like a diminutive, sickly woman in her 80s. In reality she was only 15 years old, a victim of progeria, an extremely rare genetic disorder caused by a single mutation in one of 3 billion base pairs that make up human DNA. Completely normal in mind and spirit, children with progeria age at a very rapid pace, typically dying in their teenage years.
Rose captured the hearts of her more than 3 million YouTube subscribers and 12 million Facebook followers with a cheerful, positive outlook and zest for life. With her mother's help, she shared details of her painful and debilitating disease via upbeat, charming videos, while leaving plenty of room for her dance moves and numerous makeup tutorials.
"I look sexy!" she told her audience, flipping her blue-tipped blond hair over her shoulder with Lizzo flair, before settling down to explain to her viewers the types of medicines she took and why she lost vision in one eye.
While Rose spent her short life helping to break down the stigma attached to a devastating illness, geneticist David Liu has dedicated his career to developing ways to alter the genetic code that took her life at such a tender age.
"That a single misspelling in her DNA ended Adalia's life so early is a loss for all of us," said Liu, a professor of chemistry and chemical biology and director of the Merkin Institute of Transformative Technologies in Healthcare at Harvard University.
"I did not get the chance to meet Adalia before she passed away in January. But every progeria patient I have met has been warm, charming, articulate and profoundly inspiring," Liu told CNN.
In his Harvard lab, Liu and his team have invented new ways to repair mutated genes that are less damaging to DNA than prior technologies. One of his lab's major innovations is a base editor, a tool that can correct misspellings in the four most common bases in DNA, Liu told an audience at Life Itself, a health and wellness event presented in partnership with CNN.
"These misspellings in our DNA collectively caused thousands of disorders that affect hundreds of millions
of people and their families," Liu said.
These four DNA bases -- adenine (A), cytosine (C), guanine (G) and thymine (T) -- form specific pairs that are always supposed to be matched with each other: A with T, and G with C.
Last year Liu and his team used a base editor to tackle the misplaced genes of progeria in mice. He's hopeful clinical trials for children with progeria could begin in the near future.
"The base editor goes into the cells of the animal, looks for the mistake, which in progeria is a C to a T and changes the T back into a C," said Liu, who is also vice-chair of faculty at the Broad Institute of MIT and Harvard, a biomedical and genomic research center in Cambridge, Massachusetts.
Liu's team further discovered that base editors worked especially well if you "nick" the unedited strand of the DNA double helix, coaxing the cell to copy the desired edit onto the second strand.
"And that's it. We never come back into the patient -- it's a one-time treatment that permanently fixes the mutation that causes the disease," Liu said.
Six months after announcing success with progeria, Liu and scientists at St. Jude Children's Research Hospital announced they had used base editors to reverse sickle cell disease in mice.
"The age of human therapeutic gene editing isn't just coming. It's already here," Liu told the Life Itself audience.
https://www.cnn.com/2022/05/31/health/reversing-genetic-fate-scn-wellness/index.html
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