Showing posts with label gene editing. Show all posts
Showing posts with label gene editing. Show all posts

Sunday, November 12, 2017

Clinical somatic gene editing could be a reality, human enhancement is still a distant shot says the Bioethics committee

https://geneticliteracyproject.org
It is nearly four years ago, scientists reported that clustered regularly interspaced short palindromic repeats-Cas9 (CRISPR-Cas9) technology can enable precise and efficient genome editing in living eukaryotic cells. Since then, scientists are looking for feasibility of successful somatic and germline editing to eliminate many devastating genetic diseases. But, it also comes with a thorny international debate as it opens the door to designer babies and engineered humans.

On August 2, 2017, scientists at the Oregon Health & Science University reported that they had succeeded for the first time in United States in correction of the dominant MYBPC3 mutation that causes a late-onset familial version of hypertrophic cardiomyopathy using CRISPR/Cas9. 


What is DNA editing


One day after this paper was published in Nature, the American Society of Human Genetics (ASHG), and 11 organizations including representatives from the UK Association of Genetic Nurses and Counsellors, Canadian Association of Genetic Counsellors, the International Genetic Epidemiological Society, and the US National Society of Genetic Counselors, as well as the ASHG,  published a joint statement in August concentrating on the prospects for germline alteration. 

The statement as published in the AmericanJournal of Human Genetics, again reiterated that clinical use of germline editing is not allowed at present- these are genetic changes that would be in every cell of a resulting baby and be passed on to future generations, viewed as ‘ethical violation’ by many.  
On the plus side, it provides the only hope for some parents who are carriers of genetic diseases with their best or most acceptable option for having genetically related children who are born free of these diseases. 

Germline somatic editing has already entered clinical trials for non-heritable applications, for treating or preventing diseases or disabilities at this time.

There are three important differences between the two approaches.
1.     Somatic therapies target genes in specific types of cells (lung cells, skin cells, blood cells, etc), while germline modifications, applied to embryos, sperm or eggs, alter the genes in all the resultant person’s cells.
2.      Somatic cell modifications are not biologically transferred to next generations, so it only affects one individual.  Germline editing would be inheritable, have greater impact as it would affect the generations to come.
3.     Clinical trials involving somatic cell therapies are around over two decades now, while human germline editing studies have only just begun this year.

There are a host of unanswered ethical and scientific dilemmas, around the procedure but it does not deny the prospects of germline editing, if the ethical and policy guidelines are met. More stringent regulations would need to be in place, to ensure safety and efficacy when tinkering with human nature

Currently, heritable germline editing is not permissible in the United States.  It is only allowed for purpose of research as the statement published in the American Journal of Human Genetics after 16 months of deliberation, “Currently, there is no reason to prohibit in vitro germline genome editing on human embryos and gametes, with appropriate oversight and consent from donors, to facilitate research on the possible future clinical applications of gene editing.”

It suggested that research into genetic modifications should continue as long as it doesn’t lead to a pregnancy.

This ASHG statement is the second set of recommendations issued in 2017, following an exhaustive 300 pages NationalAcademy of Sciences, Engineering, and Medicine (NASEM) document “Human Genome Editing: Science, Ethics, and Governance.” 

The NASEM statement is more wide and covers somatic gene editing, but both the statements expressed reservations currently on using germline editing for creating ‘engineered humans’, but did not deny the possibility of it in future.

Both statements also called for public funding, for manipulating human embryos and fetuses for research, arguing that without funds the research may move offshore, where less stringent regulations and transparency prevails and that may result in rogue experimentation.

Human genome editing is already widely used in basic research and is in the early stages of development and trials for clinical applications that involve non-heritable (somatic) cells.

The Chinese and U.K laws are already in place.

Biologist Paul Knoepfler estimates that genetically modified people will no longer be a science fiction fantasy; it's a likely future scenario. Within fifteen years, scientists could use the gene editing technology CRISPR to make certain "upgrades" to human embryos — from altering physical appearances to eliminating the risk of auto-immune diseases. 

As Victor Hugo said, “there is nothing more powerful than an idea whose time has come.” So, now it’s a question of “when”, instead of “never”.
Here is a video by Françoise Baylis, a philosopher and professor at Dalhousie University, is one of the foremost voices among bioethics scholars worldwide.

Her mission is to foster an inclusive dialogue on what should and should not be allowed through gene editing. As the consequences of these decisions will affect future generations





Monday, March 13, 2017

CRISPR co-inventor Jennifer Doudna keynote address about responsible use of gene editing in future.

“What if a cell’s DNA could be edited just like the text of a document so that you could actually erase letters, you could erase whole sentences, [you could] replace sentences, and you could do things that would enable scientists to change the mutations that might cause genetic disease, make changes that allow us to understand the function of DNA and different kinds of organisms and perhaps, enable us to really direct the way that organisms are evolving on the planet?”

With this promising words about future of CRISPR Cas9 technology Jennifer Doudna, co-inventor of CRISPR Cas9 technology started her keynote address at 2017 South by Southwest (SXSW) conference.

The whole invention of CRISPR Cas9 technology is a result of curiosity developed research project aimed at understanding how bacteria fight viruses. It started as adaptive immune system in bacteria that could be harnessed into a powerful gene editing tool that will have profound influence on the world. What started in academic laboratory and is now adopted by clinicians, scientist, government regulatory agencies and commercial companies to develop the technology for human applications for eliminating many genetic diseases.  This is a very young technology ( 5 years )which is evolving very rapidly. 

She further cited many examples where the CRISPR Cas9 technology will find application in animals and plants. It’s application in plants could change the way we look at GMO foods. It can be used to create gene drivers that enable us to drive a trait through population very rapidly. This can be used in near future to create mosquitos that are resistant to infections, thereby limiting the spread of disease.
It will also increase our understanding of why certain genetic traits in a population makes them resistant to develop cancer.

Another application of the Cas9 technology is using it to create animals that are better suited for organ donors.  In principle, we can create organ donor pigs that are better suited for human organ replacement. 

In humans, one of the earliest clinical trials regarding the clinical application of using Cas9 gene editing technology will be to correct the mutation that causes sickle cell disease and is expected to start in couple of years.

Clinical trials are already ongoing in China and USA to make changes in immune system of cancer patients to make their immune cells capable of finding cancer cells  and mounting an immune response in destroying these cells.

All these are somatic applications of the amazing technology, it can also be used for altering the germ cells. Germ line editing application of Crispr technology is surrounded by ethical dilemmas because whatever changes are made will be transferred to coming generations.

It gives us powers to make changes to DNA that will be inherited by future generations. We will be creating traits that we consider enhancement and creating super humans.

Creating Superhumans: From Jennifer Doudna keynote speech.

At present human embryo editing, is only allowed for research purpose till 14 days stage of development and not for clinical use to get pregnant till the ethical and moral considerations are addressed fully across international borders.

She concluded her lecture by iterating her interest of developing this technology further by engaging and educating with public about ethical use of CRISPR for gene editing for treating genetic diseases and not for some sort of harmful effects.

She invited the public to visit the website of Innovative Genomic Institute, a partnership between  UC San Francisco and UC Berkeley which educates the public about coordination between various  institution to go forward with application of this technique in agriculture and responsible use in  human beings. 

Dr. Jennifer Doudna, Ph.D. was named one of Time Magazine’s 100 Most Influential People in 2015.  She is a professor of molecular and cell biology and chemistry at the University of California, Berkeley, where she holds the Li Ka Shing Chancellor’s Chair in Biomedical and Health Sciences and is a Howard Hughes Medical Institute investigator.

Here is the full lecture at the SXSW conference,2017.