Posted by on April 1, 2018 7:50 pm
Categories: Crispr Articles

Source: Co-inventor: CRISPR gene editing could have 'profound positive effect,' but ethics concerns remain

SALT LAKE CITY — Jennifer Doudna, who co-invented a gene editing technology that could transform how numerous genetic conditions are treated, says the process not only raises many hopes, but also brings concerns about “designer babies.”

Doudna, a professor of biochemistry and molecular biology at the University of California-Berkeley, is one of the authors of a 2012 paper describing a defense mechanism used by bacteria as the basis for a technology allowing for the precise, detailed editing of organisms’ DNA, including that of humans.

That technology, called CRISPR Cas9, has been used successfully to meticulously change specific genetic traits in multiple species, including monkeys, mice and certain plants.

Doudna and other scientists have said CRISPR Cas9 can revolutionize the fight against genetic disease in humans. But she has also warned that its wide-ranging capacity to alter genes will inevitably lead to various ethical dilemmas about a range of issues — including the eventual prospect of “CRISPR babies,” or so-called designer humans pre-selected to have certain traits even before they are born.

Doudna, who recently gave a lecture at the University of Utah, talked with the Deseret News about scientists’ efforts to use CRISPR Cas9 to defeat genetic disease and the moral considerations arising from the technology.

The following conversation has been edited for length and clarity.

DN:You mentioned a few years ago that you had called for a pause on certain clinical uses of CRISPR Cas9… . In your view, how well has that moratorium been honored generally across the world and what is your assessment of how the conversation on ethics has been going?

Doudna: (Scientists) who had been part of that original conversation (about) molecular cloning, they helped us to think about how one might call for the scientific community to essentially … refrain from any kind of use of human embryo editing.

(What I mean is) changing the DNA in human embryos and then implanting those embryos so they could lead to a pregnancy and a “CRISPR baby.”

That original call for a moratorium on that kind of application has actually held.

…However what has happened, and I think this is really a sign of what’s coming in the future, is there’s been very active efforts at the research level to use CRISPR Cas9 gene editing in human embryos, including in viable human embryos, meaning embryos that could in principle be implanted. So that means that increasingly, any technological barriers to doing that kind of work are being removed.

I think that it means the day in which it will be possible, technically, to use this technology in human embryos for the purposes of creating a CRISPR-modified person is approaching quickly. And I think that that really indicates that we need to be having these kind of discussions and figuring out how we’re going to grapple with this technology that is so powerful.

DN:What are these ethical dilemmas that could potentially be presented when we get to that point?

Doudna: There really are three areas that I think about.

One is the human embryo editing. We could call it germline editing. It basically just means making changes that are heritable in DNA in humans, that can inherited by future generations.

And just to be clear, that’s distinct from the idea of using gene editing in an adult, or a patient, in cells that are not part of the germline (in which affected genes are) not eggs or sperm, so the changes to DNA would not be passed to future generations.

And I think most people feel that that kind of (non-germline) application is really not ethically fraught. It’s something that would affect one person and it needs to be treated as one would treat any other kind of therapeutic for safety and effectiveness, but doesn’t affect future generations.

(The second ethics question) is applying the CRISPR Cas9 technology in agriculture. And that raises the whole question of how do we define genetically modified organisms, or GMOS.

That (has) led to really a fascinating ongoing debate/discussion in many countries about how do we define GMOs and (when) CRISPR Cas9 (is) used in plants, does that lead to plants that we would consider … GMO.

…I think the third area of (ethical) application is something called gene drive. And that simply means using this technology in a way that drives a genetic trait very quickly through a population, for example a population of insects like mosquitoes that would lead to, for example, either preventing mosquitoes from being able to transmit disease or even prevent mosquitoes from being able to reproduce.

Again there’s this sort of pros and cons. This could have an incredibly positive impact on human health if we could prevent mosquito-borne diseases from being spread, like Dengue virus, Zika, etc. But it also raises the possibility of unintended environmental consequences and how do we control something like that once it’s unleashed.

DN:Who needs to be around the table for ethics conversations like this, and how well is the scientific community doing in getting these particular groups to the table?

Doudna: I think that the more that this kind of discussion can happen with a broad spectrum of stakeholders, the better.

And it turns out it’s a big, big challenge, because first of all there’s just the fact that there’s just some technical details that have to be explained so that people can kind of understand, first of all, what is this technology. And even without getting into the weeds about how it works they need to understand at least at a basic level what it is we’re talking about.

And then it’s really about kind of helping different kinds of stakeholders to get together, and I’m talking about people who whether they’re clinicians, or people that work in various industries like in the agriculture industry, (or) people who are affected by genetic diseases in their families. I routinely hear from people who … are grappling with profound issues having to do with genetic disease and they really want to understand what is this going to mean for their future or their kids’ future.

Then it’s really just a challenge I think to try to find venues where people can come together and discuss ideas that frankly lead to very different points of view.

DN:Just in terms of pure capacity to move this into clinical settings, for example to help patients with illnesses brought on by genetics, can you give me an idea of how close we are to that?

Doudna: One thing to point out is that right now there are already something like four clinical trials already happening in China and the U.S. to use the CRISPR Cas9 genome editing technology in patients that have cancer. And the idea there is really to harness the patients’ immune system to target cancer and use gene editing to give the immune cells the right genetic information so they can go after the tumors efficiently. So those are already starting.

What I think we’re going to see going forward, maybe as soon as in the next 18 to 24 months, is probably multiple clinical trials that will begin for specific kinds of genetic diseases, and I think the earliest targets will probably be eye diseases as well as blood diseases.

And the reason there is that these are tissues that are easier to deliver these editing molecules into than for other systems.


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DN:What is the scope of the kinds of illnesses that CRISPR Cas9 can address long term?

Doudna: There’s something like 7,000 known human disorders that stem from a single mutation in the DNA — so a single gene that’s affecting a person’s health. So those are the most likely targets for this anytime in the near future, because it’s much harder if you have a disease or a trait in somebody that results from say 100 or 500 genes that all contribute a little bit.

So I think that disorders where there’s a well-known mutation that could be corrected are going to be the earliest targets.

Published at Sun, 01 Apr 2018 17:31:00 +0000

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