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





Tuesday, February 14, 2017

US National Academics report paves the path forward for genetically modified babies with proper guidelines.

Courtesy: Business insider 
  

The US National Academies of Science, Engineering, and Medicine today submitted a report laying down guidelines for  genetically modifying human embryos to eliminate devastating genetic conditions.


This 261page report follows the conclusion of 2015 International Summit on Human Gene Editing. It took multidisciplinary committee experts a full year to perform in depth review of literature, monitoring the latest advancement and getting input from all the prominent players in field of human gene editing.

The committee set forth specific criteria before experimentation and clinical trials can begin regarding these heritable germline  mutation. The criteria for heritable germline editing by National Academy of Science and National Academy of medicine are:[1]

  1. Absence of reasonable alternatives
  2.  Restriction to preventing a serious disease or condition
  3.  Restriction to editing genes that have been convincingly demonstrated to cause or to strongly predispose to the disease or condition
  4. Restriction to converting such genes to versions that are prevalent in the population and are known to be associated with ordinary health with little or no evidence of adverse effects
  5. Availability of credible pre-clinical and/or clinical data on risks and potential health benefits of the procedures
  6. Ongoing, rigorous oversight during clinical trials of the effects of the procedure on the health and safety of the research participants
  7.  Comprehensive plans for long-term, multigenerational follow-up while still respecting personal autonomy
  8. Maximum transparency consistent with patient privacy
  9. Continued reassessment of both health and societal benefits and risks, with broad on-going participation and input by the public
  10. Reliable oversight mechanisms to prevent extension to uses other than preventing a serious disease or condition

At present genome editing, should not be used for creating designer human beings  with all the chosen, positive  traits.

Alta Charo, a bioethicist at the University of Wisconsin–Madison and co-chair of the report said “Up until now, we’ve been talking only hypothetically and most people assumed we simply wouldn’t ever do this. We are not saying that you have to or you should, but we are saying that if you can meet these criteria it is permissible.”

Many researchers who opposed the gene editing technique where disappointed by the green signal.
George Church, a geneticist at Harvard University in Cambridge, Massachusetts opined that it is difficult to draw a line between medical use and creating ‘super humans’. 

Scientist also expressed concerns over ‘Medical tourism’ as scientist working in countries with less stringent regulation will start modifying embryos for purpose other than medical reasons. 

The complete report can be download here
The summary of recommendations can be found here
The principles for the governance of Human Genome Editing can be found here.  





[1] http://nationalacademies.org/cs/groups/genesite/documents/webpage/gene_177255.pdf