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Science Policy Around the Web December 6th, 2019

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By Hannah King, PhD

Image by Steve Buissinne from Pixabay 

200,000 Uninsured Americans to Get Free H.I.V.-Prevention Drugs

World AIDS Day, held annually on December 1st, has led to a flurry of AIDS-related announcements this week.

The Trump administration has released an announcement outlining how it plans to distribute HIV prevention drugs donated by the pharmaceutical company Gilead, which manufactures the drugs. These drugs will be available to 200,000 uninsured Americans who have a prescription and recent evidence of their HIV-negative status.

While other programs exist in the US to provide these drugs free of charge (including those run by cities in high-incidence areas and a program from Gilead itself) this announcement marks the first time the government has provided such HIV-prevention medicine free to individuals not enrolled in a federal health program. With 37,500 new HIV infections per year in the US, and 1.2 million Americans estimated as being at high risk for HIV-acquisition, widespread distribution of this preventative treatment is an important public health initiative. 

Access to HIV prevention and treatment medication is also a worldwide issue. In further encouraging news, an Indian drug manufacturer has announced that it will make a pediatric formulation of HIV medication, that is strawberry flavored and the size of sugar granules! The current medication is either formulated as hard tablets, or requires refrigeration, reducing either the tolerability to children or accessibility of the product. As 160,000 children are born with HIV each year, but only approximately half receive treatment, this new formulation will hopefully reduce the AIDS-related morbidity and mortality in this vulnerable population.   

(Donald G. McNeil Jr., New York Times

China’s CRISPR babies: Read exclusive excerpts from the unseen original research

Further details of the research purporting to use CRISPR to create gene-edited babies have emerged, reinforcing the “serious, unresolved safety concerns” associated with this human research. 

MIT Technology Review has released excerpts from an unpublished manuscript outlining a study by the Chinese researcher He Jiankui which describes the creation of the first gene-edited human babies. The mutation introduced into the embryos is a deletion in the gene expressing a protein called CCR5. A deletion in this CCR5 protein occurs naturally in some individuals and renders them resistant to infection with HIV – the stated rationale for this experiment. However, the manuscript shows the deletion that was introduced into the genomes of these babies is similar, but not identical to the naturally occurring deletion, and no attempt is made by the authors to validate its ability to confer HIV resistance.

Furthermore, despite the manuscript describing the experiments a “success”, the data shows the CCR5 deletion is absent in one chromosome on one of the babies, meaning she carries one copy of the functional CCR5 gene, and is still susceptible to HIV infection. Data in the manuscript, showing DNA sequencing of cells from the babies following their birth also indicates that not all cells in these babies share the same genetic code, suggesting that not all cells carry the CCR5 deletion, or that other “off-target” effects with unknown health implications may be present.

This newly available data, in addition to the many ethical concerns previously raised, further demonstrate this experiment is not the “success” nor the path forward to “control the HIV epidemic” that He Jiankui claims it to be.

(Antonio Regalado, MIT Technology Review)

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December 6, 2019 at 1:51 pm

Science Policy Around the Web October 29th, 2019

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By Allison Cross PhD

Image by Gerd Altmann from Pixabay 

Super-precise new CRISPR tool could tackle a plethora of genetic diseases

Since the first adaption of CRISPR-Cas9 for gene editing in eukaryotic cells in 2013, the hopes of using the technique to cure genetic diseases have been high.  Despite the ability of current CRISPR–Cas9 gene-editing tools to edit the human genome, successful edits are often accompanied by unintended and unpredictable errors elsewhere in the genome. However, a new method of editing, published this week in Nature, shows potential for greater control over genome editing.   

This new method of genome editing, referred to as prime editing, still uses Cas9 to recognize specific DNA sequencing in the genome.  However, instead of producing double stranded breaks, a modified Cas9 enzyme is utilized to cut only one strand of the DNA.  The cut strand of DNA (called nicked DNA) is then repaired utilizing a prime editing guide RNA, known as a pegRNA.  

Prime editing offers several advantages over a similar previously developed editing technique, known as base editing.  Base editing, like prime editing, does not result in double stranded DNA breaks; instead it allows researchers to make specific substitutions to the bases that make up DNA (adenine, guanine, thymine, cytosine). However, it only allows for certain subsets of single base changes to be made (C->T, G->A, A->G, and T->C).   Prime editing is more versatile, allowing for all 12 possible base-to-base changes and capable of making multi-base changes.  There is, however, a limitation to how large the changes can be using the prime editing technique.  If large insertions or deletions are desired, traditional CRISPR-Cas9 tools remain necessary.

Researchers are still evaluating how prime editing works in a variety of cells and organisms, but the initial studies published this week show promise for more versatile and precise gene editing with fewer unwanted byproducts. 

 (Heidi Ledford, Nature) 

U.S. Travel Ban Disrupts the World’s Largest Brain Science Meeting

The travel ban implemented by the Trump administration restricts U.S. travel from 7 nations; Iran, Librya, Somalia, Syria, Yemen, North Korea and Venezuela.  The ban has been a very controversial issue with wide ranging implications. After its implementation, many in the scientific community feared the ban would hurt the community by resulting in lost potential collaborators, trainees, and recruits.  

This year’s Society for Neuroscience meeting drew more than 25,000 brain scientists from around the world to Chicago this week, however, some scientists were unable to attend due to visa issues. Sepiedeh Keshavarzi, a current Australian citizen who holds an Iranian passport, was invited to give an oral presentation during the year’s meeting. Instead of attending the meeting in person, Keshavarzi instead sent a prerecorded PowerPoint presentation to the meeting after her request for a Visa to the U.S. was denied.  

With Visa problems becoming increasing common, the Society to Neuroscience created a special program aimed at helping scientists with Visa issues present their work at this year’s meeting. The program, called Science Knows No Borders, did help some scientists, like Keshavarzi, present their work; however, fewer than a dozen scientists participated in the program. 

(Jon Hamilton, NPR)

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October 29, 2019 at 2:47 pm

Science Policy Around the Web October 25th, 2019

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By Andrew Wright BSc

Image by Arek Socha from Pixabay 

NIH and Gates Foundation lay out ambitious plan to bring gene-based treatments for HIV and sickle cell disease to Africa

Following the launch of an initiative to boost gene therapy treatments of sickle cell disease last month, the National Institutes of Health (NIH) and the Bill and Melinda Gates foundation have announced a joint funding agreement of at least $100 million over the next four years to expedite a cure for both sickle cell disease and HIV and make it available in Africa. 

The current medical intervention for sickle cell disease is a bone marrow transplant, a treatment that is limited by the availability of genetically compatible donors and can be risky for adult patients. This new partnership aims to build on funding towards more effective treatments that are less restricted and more cost effective. While genetic intervention is being used in a limited clinical setting, it is still necessary to destroy a patient’s stem-cells via chemotherapy before reintroducing the patient’s genetically modified ones. Using burgeoning gene-editing techniques such as CRISPR, researchers for this initiative hope to modify targeted genes with a process more similar to a blood transfusion using replication-deficient viruses or nanoparticles to carry the molecular tools to where they need to be. This should theoretically make treatments much less expensive and more available to regions that have limited medical infrastructure and a high incidence of sickle cell disease such as sub-Saharan Africa. 

Since there is also a high incidence of HIV in sub-Saharan Africa, this initiative also aims to tackle HIV in the region using similar techniques. The current standard for treating HIV is anti-retroviral therapy, which can allow patients to live a normal life, but also must be taken every day, is expensive ($429-$10,896 per month), and does not eliminate the disease. The drive behind genetic intervention strategies comes from serendipitous case-studies when two men were cured of HIV following stem cell transplants that intentionally had white-blood cells with a weakened protein to treat their blood cancers. The NIH-Gates funding initiative will focus on strategies to weaken these proteins (called CCR5 receptors) and to directly destroy HIV genetic material.

(Jon Cohen, Science)

Evidence links poliolike disease in children to a common type of virus

Since 2014 more than 570 children have experienced a condition known as acute flaccid myelitis (AFM) where some suddenly lost limb control, had trouble swallowing or breathing, or ended up paralyzed. These symptoms routinely followed symptoms of a common cold, like a runny nose or fever. Up until now, the route cause behind AFM was not well understood, but recent studies of patients’ spinal fluid suggest the culprit is enterovirus. Infections from enteroviruses are common and rarely cause severe symptoms (although they can cause respiratory illness in asthmatic populations). 

Previous studies into the cause of AFM had examined enterovirus but found no trace of it in the central nervous system, where it would need to be in order to lead to loss of motor control. In the most recent study conducted by the University of California San Francisco, researchers sampled for elevated levels of antibodies in the central nervous system rather than the virus itself. They found that 69% of AFM patients had elevated antibodies against enteroviruses. There are still questions as to why only some children experience AFM when infected by enterovirus when most only experience typical symptoms.

Unfortunately, enterovirus-AFM is currently untreatable beyond post-infection physical therapy, although the lead author of the study suggests that immunoglobin therapy may help reduce the worst symptoms. Ultimately, the only way to completely prevent enterovirus-AFM infections, referred to by some as ”the new polio“,  will be a vaccine.

(Kelly Servick, Science)

Written by sciencepolicyforall

October 25, 2019 at 3:39 pm

Science Policy Around the Web August 1st, 2019

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By Andrew Wright BSc

Image by Steve Buissinne from Pixabay 

Major U.S. cities are leaking methane at twice the rate previously believed

While natural gas emits less carbon dioxide (CO2) when burned, if allowed to enter the atmosphere as methane (CH4) it can act as a greenhouse gas that is 20-80 times more potent than CO2. Some of this impact is supposed to be mitigated by the relatively low amount of leaked methane, roughly 370,000 tons in six major urban areas studied according to a 2016 report from the EPA. However, a new study in the journal Geophysical Research Letters analyzed those same metropolitan centers and found that the EPA has underestimated methane release by more than half. By taking simultaneous measurements of ethane, which appears only in natural gas supplied to homes and businesses, researchers were able to delineate the sources of leakage, as natural sources and landfills do not give off ethane. 

From their analysis, the total estimate from the six cites studies was 890,000 tons of CH4, 84% of which was from methane leaks. While the authors of the study are unsure as to why the EPA estimates are so low, they suggest it could be because the EPA only estimate leaks in the distribution system, rather than endpoint leaks in home and businesses. While these results cannot be reliably extrapolated to newer cities which may contain infrastructure more resilient to leakage, they could engender further study to gather a clearer picture of national methane release.

(Sid Perkins, Science)

 

Japan approves first human-animal embryo experiments

On March 1st the Japanese science ministry lifted a ban on growing human cells in animal embryos and transferring them to animal uteri. While human-animal hybrid embryos have been made before, functional offspring have not been allowed to develop.  The first researcher to take advantage of this new regulatory scheme is Hiromitsu Nakauch, the director of the Center for Stem Cell Biology and Regenerative Medicine at the Institute of Medical Science at the University of Tokyo and a faculty member at Stanford University. His long-term goal is to grow human organs in animals such as pigs, from which the functional organs could be extracted and transplanted into human patients. His intent is to start in an early embryonic mouse model, then a rat model, and finally a pig model with embryos that form for up to 70 days. 

This measured approach is in stark contrast to the recent controversy regarding CRISPR edited babies in China, but has still been met with a certain level of ethical skepticism. Bioethicists are particularly concerned that the human cells being injected into animal embryos, induced pluripotent stem (iPS) cells, may deviate from their intended target (in this case the pancreas) and affect the host animal’s cognition. According to Nakauchi, the experimental design, which involves eliminating the gene for the target organ and injecting human iPS cells to compensate, is such that the cells should only be involved in a specific part of the animal. 

While Nakauchi’s group used this method to successfully grow a pancreas in a rat from mouse cells, they have had limited luck putting human iPS cells into sheep embryos. Given the evolutionary distance between mice, rats, pigs, and humans it may be difficult for experimenters to produce more satisfactory results. To address this Nakauchi has suggested that he will be trying genetic editing techniques as well as using various developmental stages of iPS cells.

(David Cyranoski, Nature)

 

 

Written by sciencepolicyforall

August 1, 2019 at 12:23 pm

Gene editing- Regulatory and ethical challenges

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By: Chringma Sherpa, Ph.D.

Image by Colin Behrens from Pixabay 

When power is discovered, man always turns to it. The science of heredity will soon provide power on a stupendous scale; and in some country, at some point, perhaps, not distant, that power will be applied to control the composition of a nation. Whether the institution of such control will ultimately be good or bad for that nation, or for humanity at large, is a separate question.

William Bateson, English biologist who coined the term “genetics.”

On November 25, 2018, in an allegedly leaked YouTube video, He Jiankui, a scientist at the Southern University of Science and Technology in Shenzhen, China, revealed the birth of the first gene-edited babies using a technology called CRISPR. There has been a general consensus in the scientific community that heritable changes should not be made to prevent the off-target and unwanted genetic changes artificially produced in an individual during gene editing to be passed on to his/her offspring(s). He became the first scientist to publicly violate this consensus resulting in an international scandal and criminal/ethics investigations into both He and his collaborators.

In the wake of He’s CRISPR-babies scandal, scientists worldwide are debating on the ethical and regulatory measures that would discourage another wayward and rogue scientist like He from attempting such an irresponsible feat.  At the 2nd international summit on human gene editing that convened two days after He’s video became public, He presented his work. The summit was well attended by ethicist and journalist besides scientists. At the summit, David Baltimore of the California Institute of Technology, who chaired the organizing committees for both the 1st and 2nd international summits on human gene editing read one of the conclusions from the 1st summit held at Washington DC in 2015 – “It would be irresponsible to proceed with any clinical use of germline editing unless and until (i) the relevant safety and efficacy issues have been resolved, based on appropriate understanding and balancing of risks, potential benefits, and alternatives, and (ii) there is broad societal consensus about the appropriateness of the proposed application”. Baltimore called He’s work outright irresponsible on the basis of the statement from the 1st summit. At the summit, many other ethical and safety-related questions were raised which He failed to answer or did not answer convincingly. 

He’s scandal has driven various organizations to draft new guidelines and sanctions aimed at preventing unethical and unapproved use of genome editing.  China has imposed new laws requiring human gene editing projects to be approved by China’s health ministry first to avoid fines and blacklists. Both the 2nd human gene editing summit and the WHO panel that convened in March 2019, have proposed a central registry of human gene-editing research and called for an international forum/ committee to devise guidelines for human gene editing based on common norms and differences of opinions between countries.  To allow time for the creation and effective implementation of new regulations, the WHO also called for a global moratorium on heritable editing of human eggs, sperm, or embryos for the next five years. Supporting the WHO panel’s recommendations, Francis Collins, director of the National Institute of Health, said that “NIH strongly agrees that an international moratorium should be put into effect immediately”. However, not all scientists are in favor of a moratorium, as they believe it might stifle the growth of a technology that might be safe and beneficial in the near future. Jennifer Doudna of the University of California, Berkley, one of the co-inventors of CRISPR gene editing, says that she prefers strict regulation that precludes the use of germline editing until scientific, ethical, and societal issues are resolved over a moratorium. David Baltimore agrees with Doudna stating that the word moratorium was intentionally not used in both the human gene editing summits as a moratorium would be hard to reverse.  Science historian Ben Hurlbut of Arizona State University, who had numerous discussions with He before Lulu and Nana were created, thinks a blanket moratorium on clinical germline editing would have prevented He from proceeding. Both the two human gene editing summits and a 2015 essay by Baltimore, Doudna, and 16 co-authors had already outlined numerous guidelines for clinical germline editing. According to Hurlbut, He weighed these criteria and believing that his procedure met all the guidelines proceeded. A categorical prohibition of germline editing would not have allowed him to use his subjective judgment and act out of self-interest. 

The modern debate over CRISPR editing is not the first time the scientific community has come together to discuss game-changing biological technologies, and it is heavily informed by two prior events. In 1970, Paul Berg and his postdoctoral researcher David Jackson used the recombinant DNA technology to create the first chimeric DNA. This invention created an uproar among the scientists and the general public who feared that this technology would lead to the creation of uncontrollable and destructive superbugs, the exaggerated versions of which can be seen in some science fiction movies. Yielding to the opinions and sentiments of the fellow scientists, Berg held himself from cloning such recombinant DNAs and in 1974, he pleaded for a voluntary moratorium on certain kinds of recombinant DNA research until their safety issues have been resolved.  He also moved quickly to organize the Asilomar conference (Asilomar II) in 1975 that bore semblance to the 2nd human gene editing conference in that it invited not only the scientists but lawyers, ethicists, writers, and journalists to weigh in on the risk-benefit analysis of the Recombinant DNA technology. On the recommendation of Asilomar conference, Donald Fredrickson, then director of the National Institutes of Health (NIH), initiated the formation Recombinant DNA Advisory Committee (RAC) to act as a gatekeeper of all research that involved recombinant DNA technology. The scope of the committee, which was composed of stakeholders, including basic scientists, physicians, ethicists, theologians, and patients’ advocates was later expanded to encompass the review and approval of human gene therapy research. Due to the redundancies of regulatory oversights between the US Food and Drug Administration (FDA) and RAC, RAC was reinstated as only an advisory body providing advice on the safety and ethical issues associated with emerging biotechnologies in 2019.

While this is a successful example of scientific self-regulation, the second event resulted in a major setback in the field of gene therapy. On September 13, 1999, Mark Batshaw and James Wilson of University of Pennsylvania supervised the administration of adenovirus to an 18-year-old Jesse Gelsinger in a gene therapy clinical trial. Gelsinger died of liver and kidney failure and brain damage three days later. Like the birth of CRISPR babies, Gelsinger’s death was an instance where new technology was used prematurely without a thorough assessment of its safety profile. It is suspected that both the clinical applications headed by He and Wilson might also have been motivated by fame and financial gain; He and Wilson both had financial stakes in private biotechnology companies that would benefit from these human trials. In the aftermath of Gelsinger’s death, Wilson was banned from carrying out FDA regulated clinical trials for the next five year, nearly all gene therapy trials were frozen, and many biotechnology companies carrying out these trails went bankrupt. This was a dark period in the history of gene therapy, and it would take almost another decade of introspection, reconsideration, and more basic experimentation for gene-therapy to re-emerge as a viable therapeutic strategy.

Figure 1: The regulatory status of human germline gene modification in various countries. Thirty-nine countries were surveyed and categorized as “Ban based on legislation” (25, pink), “Ban based on guidelines” (4, faint pink), “Ambiguous” (9, gray), and “Restrictive” (1, light gray). Non-colored countries were excluded in this survey. Adapted from Araki, M. and Ishii, T (2014): “International regulatory landscape and integration of corrective genome editing into in vitro fertilization” Reproductive Biology and Endocrinology, 2014 12:108

Scientists at both the Asilomar and human gene editing conferences passionately debated the safety of the relevant technologies but deliberated on the discussion of the big ethical issue associated with these technologies – the ultimate creation of designer babies. That gene editing sits on the slippery slope to eugenics was recognized since the days of Charles Darwin and Gregor Mendel when the study of genes and heredity was still in its infancy and the discovery of DNA as the genetic material was half a century away. One of the earliest proponents of genetic manipulation for human benefits was Francis Galton, Charles Darwin’s cousin. Galton proposed an unnatural and accelerated selection of beneficial traits by marriage between people of desirable traits. The danger that someday some rogue scientists might use germline gene editing technology in favor of eugenics lurks in the mind of those who understand the potential of the currently available gene editing technologies. However, more fearful is the idea that the wave of positive eugenics would soon give way to negative eugenics – elimination of undesirable traits as it did around World War II as exemplified by the famous case of Carrie Buck, a woman who was designated “mentally incompetent” and involuntarily sterilized. 

Various countries have their own regulation and legislation on germline editing to prevent any backlash from this powerful technology. Figure 1 presents a summary of the regulatory landscape of germline gene modification surveyed in thirty-nine countries by Araki Motoko and Tetsuya Ishii.  In the US, Congress has shown strong support against germline gene editing. In 1996, it passed a rider as part of the annual appropriations bill that prohibits the use of federal funds for any research involving human embryo. In another appropriations bill passed in 2015, Congress banned the FDA from considering applications involving the therapeutic modification of the human germline. 

Human gene editing holds great promises in treating many life-threatening and previously intractable diseases. Only when this discipline of science is held to high ethical standards and regulated sensibly at international, national, and a personal level, shall we reap the benefits of this powerful technology.

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May 29, 2019 at 9:25 am

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Science Policy Around the Web – May 3rd, 2019

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By: Allison Dennis B.S.

Image by Ashley Smith from Pixabay

A More Humane Livestock Industry, Brought to you by CRISPR

Innovations sparked by germline editing in livestock are poised to help farmers make rapid improvements in the care and treatment of their animals by helping overcome inefficiencies genetically. Livestock industries use animals specifically bred to maximize their use and often require or prefer animals of a particular gender. Male cattle produce more meat. Female cows produce milk. Female chickens lay eggs. Known as “the dirty secret” of the dairy industry, farmers under financial pressure may kill male calves soon after birth to avoid the costs of raising them further. Every year, 6 billion male chicks, which hold no economic value for egg production, are killed within a day of hatching. The egg industry is seeking to prevent this, and in June of 2016, the United Egg Producers, a group that represents more than 95% of egg production in the United States, stated their goal of “eliminating the culling of day old male chicks by 2020 or as soon as it is commercially available and economically feasible.”

Scientists are racing to offer these industries solutions by harnessing the power of the gene editing technology CRISPR to genetically engineer animals to break the 50-50 gender rule. Mark Tisard, a geneticist at the The Commonwealth Scientific and Industrial Research Organization, Australia’s national science agency, is using CRISPR to engineer male eggs to glow red under fluorescent light, allowing farmers to repurpose male eggs for vaccines or feed production before the chick has developed. Across the world, the startup eggXYt in Israel is taking a similar approach, making male eggs glow yellow. Alison Van Eenennaam, an animal geneticist at UC Davis, is exploring the possibility of using CRISPR to produce all male herds of beef cattle from the point of conception.

While pre-determining gender remains a major goal, gene-editing has already been used to introduce a gene for slick hair that helps cattle handle heat better in warm climates. Scientists have successfully used CRISPR to produce pigs that are resistant to the PRRS virus, which causes respiratory disease and reproductive failure, costing farmers in the United States half a billion dollars a year. 


The reception of these technologies in the United States remains unclear. Most recently, in January 2017, the FDA drafted rules that would put genetically altered animal products through the same safety and efficacy testing undertaken for new drugs. However, since then, the USDA has clarified that plants produced through genome editing will not be subject to additional regulation if they could conceivably been developed through traditional breeding methods. Those looking to harness the power of these types of genetic modifications for livestock are hoping to see this attitude expanded to animal products.

(Gregory Barber, Wired Magazine)

House Democrats move to resurrect Congress’s science advisory office

At the helm of American society is a group of appointed representatives racing to keep abreast of a deluge issues stemming from technological innovation. A draft of the 2020 Legislative Branch funding bill that was approved by its subcommittee on April 30th offers potential relief in the form of re-establishing the Office of Technology Assessment (OTA). The OTA was originally established in 1972 to provide congressional staff with deep and comprehensive analysis of technical issues to aid in the crafting of public policy, independent from lobbyists and activists. At that time, Anti-Ballistic Missiles and Super Sonic Travel were the technologies stirring up media frenzies. However, the OTA was eliminated in 1995 to reclaim $21 million for the congressional budget. The $3.9 billion dollar proposed budget for 2020 included only $6 million for its revival.

Currently, the Congressional Research Service (CRS) is tasked with keeping Congress informed on technical issues ranging from gene editing to artificial intelligence. In January 2019, recognizing the need for greater technical assistance, the US Government Accountability Office (GAO) established the Science, Technology Assessment, and Analytics team to conduct technology assessments and provide technical assistance directly to Congress. The proposed budget would support these efforts by providing CRS and the GAO an additional $24 million and $26 million respectively. However, some believe that there is still a need for the OTA in spite of these new teams. Representative Sean Casten testified to fund the OTA as he believes there is still a need to “fulfill the forward looking, deep-dive, technical assessments of new scientific and technological developments once provided by OTA.” Representative Mark Takano also expressed support, stating “In the ecosystem of legislative support organizations, OTA plays a unique role. No other entity has the capacity and expertise to provide in-depth and forward-looking analysis of complex, technical issues informed by an understanding of how Congress works.” 

Former Congressman Rush Holt similarly tried to revive the OTA in 2015, only asking for 2.5 million dollars, but his amendment was defeated 248 to164. The 2020 funding bill next heads to the full House Appropriations Committee for markup before representatives get a chance to vote.

(David Malakoff, Science)



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May 3, 2019 at 11:20 am

Science Policy Around the Web – March 15, 2019

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By: Allison Dennis. B.S.

Image by Gabriela Sanda from Pixabay 

A Genetic Mutation Might Explain Why Birth Control Can Fail

Hormonal contraceptives have been increasingly embraced as an effective tool for family planning since their approval for contraceptive use by the FDA in 1960Fewer than 1 in 100women will get pregnant in a year when using the contraceptive pill correctly, but the cause of the few unintended pregnancies remaines a mystery. 

To ask if there was a genetic reason why hormonal contraceptives might be ineffective at preventing pregnancy for some women, researchers measured the amount of etonogestrel in the blood of women using the etonogestrel contraceptive implant (Nexplanon). While the findings of this small study were not significant, the researchers did observe that women carrying a mutation in their CYP3A7gene had lower concentrations of etonogestrel in their blood. Of the women with mutation, 28% had etonogestrel levels lower than what is needed to suppress ovulation. Only 9% of women without the mutation had critically low levels. The CYP3A7 gene produces a fetal enzyme, responsible for breaking down excessive steroid hormones in the developing fetus. Usually the gene is turned off in adulthood, but genetic mutations can result in it staying active throughout one’s life, possibly leading women with these mutations to break down the etonogestrel being supplied by the Nexplanon implant. 

To begin capturing the ability of particular genetic variants to predict which patients will or will not respond to particular medication, experience adverse events, or need a particular dose, the FDA maintains a list of drugs whose use may be complicated by particular Pharmacogenomic Biomarkers. Only one of the 232 on the list is a hormonal contraceptive, listed because women carrying a particular mutation may respond negatively to one of its inactive ingredients, not because it is less effective for these women. The etonogestrel study is the first to associate particular genetic variants with birth control performance. As researchers delve into the complicated intersection between genetic differences and drug responses their discoveries promise to lead to better outcomes for all those seeking effective family planning options. 

(Megan Molteni, Wired Magazine)

New call to ban gene-edited babies divides biologists

The birth of genetically modified children is now possible thanks to technologies like the genome-editing CRISPR-Cas9which can introduce heritable changes in germline cells, including human sperm, eggs, and embryos. In November 2018, He Jiankui’s demonstrated the technique by orchestrating the birth of two babies whose genomes were altered between in vitro fertilization and implantation. He Jiankui’s experiment may have shown editing the human germline was possible, but it did not address the safety or efficacy of the genetic changes for his two inaugural patients. While many view He Jiankui’s experiment as prematureand possibly illegal, it has undeniably brought discussions of the appropriate use of the technology to a forefront. 

On March 13th, a group of prominent scientists and international specialists published a call for a global moratorium on clinically making genetically modified children. The first step, as they see it should be setting a deadline before which all clinical use of germline editing will be put on hold. They suggest five years from now. During this time, they propose that nations engage in “discussions about the technical, scientific, medical, societal, ethical, and moral issues that must be considered.” Technical issues arise from the need to demonstrate germline editing as safe and efficacious. Scientifically, the long-term effects of specific genetic enhancements or corrections must be understood. Many potential changes imagined to be possible may not be medically necessary. As for societal, ethical and moral considerations, the authors stress the importance of carefully weighing “the appropriateness of altering a fundamental aspect of humanity.” The commentary acknowledges that not all nations will be ready to proceed at the same rate but suggests that any nation that does decide to proceed only do so after consulting broadly with other countries and allowing their public to reach societal consensus that the next step is appropriate. 

The motivation of the authors’ is clear. “We’re trying to force the spotlight on what comes next,” said co-author Eric Lander, President of the Broad Institute. To what extent international consensus can be built surrounding what the National Institutes of Health calls“a crucial moment in the history of science: a new technology offers the potential to rewrite the script of human life”  remains to be seen.

(Jon Cohen, Science Magazine)

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March 15, 2019 at 4:00 pm