Tag: gene pool

Bioethics Blogs

Gene Drive Research Takes Aim at Malaria

Malaria has afflicted humans for millennia. Even today, the mosquito-borne, parasitic disease claims more than a half-million lives annually [1]. Now, in a study that has raised both hope and concern, researchers have taken aim at this ancient scourge by using one of modern science’s most powerful new technologies—the CRISPR/cas9 gene-editing tool—to turn mosquitoes from dangerous malaria vectors into allies against infection [2].

The secret behind this new strategy is the “gene drive,” which involves engineering an organism’s genome in a way that intentionally spreads, or drives, a trait through its population much faster than is possible by normal Mendelian inheritance. The concept of gene drive has been around since the late 1960s [3]; but until the recent arrival of highly precise gene editing tools like CRISPR/cas9, the approach was largely theoretical. In the new work, researchers inserted into a precise location in the mosquito chromosome, a recombinant DNA segment designed to block transmission of malaria parasites. Importantly, this segment also contained a gene drive designed to ensure the trait was inherited with extreme efficiency. And efficient it was! When the gene-drive engineered mosquitoes were mated with normal mosquitoes in the lab, they passed on the malaria-blocking trait to 99.5 percent of their offspring (as opposed to 50 percent for Mendelian inheritance).

This inheritance pattern persisted through three generations of gene-drive engineered male mosquitoes mated with normal females. With such highly efficient transmission, the researchers estimate that the malaria-blocking trait could be spread throughout an entire local population of mosquitoes in just a single breeding season by releasing one gene-drive engineered mosquito for every 100 mosquitoes in the wild.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

Gene editing and eugenics

A study published last week in the journal Cell has led to speculation that a powerful new gene editing technique is about to be developed.

Gene editing has received widespread media coverage over the past few months. Most of the excitement has centred on a specific gene editing technique, the CRISPR-cas9 system. Research conducted with CRISPR-cas9 on human embryos has been highly controversial, at least partly because some people fear it will lead to gene editing being used to alter the human germline for clinical applications, and will have unpredictable effects on future generations.

Some criticisms that have been levelled at gene editing in the wake of this research overlook the fact that it is unlikely that the cas9 system will be the specific gene editing tool used for widespread clinical applications in humans. Since the first gene editing technique was described 5 years ago, there have been 4 different gene editing systems developed, with cas9 being the latest and most accurate. But by the time cas9 would be considered for clinical applications in humans, it is likely that better gene editing tools will have been developed.The recent study published in Cell provides evidence that the enzyme Cpf1 can be used to edit genes in a more precise way than cas9.

Other objections levelled at the cas9 system apply to all gene editing techniques, no matter how advanced.  For instance, many object to gene editing on the grounds that it is eugenic, or will lead to eugenics.[5]  In justifying their call for a ban on gene editing, a recent UNESCO panel said such technologies could “renew eugenics”.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

On the Origins of Research Ethics: China and the West

by Craig Klugman, Ph.D

When I was a graduate student, I was fortunate to be one of five students chosen by the China Medical Board to attend an international bioethics conference between the U.S. and China in Beijing. We listened to talks on the philosophical bases of ethics in each country and culture. The U.S. laid its philosophical history on the doorsteps of the ancient Greek traditions such as Plato and Aristotle as well as later European thinkers such as Kant, Mill, and Bentham. The Chinese delegates talked of Confucius and Lao Tzu. We toured a hospital and a medical school. I still have a black plastic plate with the image of the medical college drawn in a gold color that was a gift to us guests.

I was assigned to a break out session where both countries were supposed to talk about values of medical ethics in the hopes of crafting an international and intercultural code of medical ethics. As a graduate student I asked the too-wise-for-my-britches question, “How can we create an international code of ethics when we are only two countries?” I was quickly quieted as the chair, an illustrious scholar, said, “Privacy. We can agree that privacy is important, correct.” There was a lot of chatter and head nodding. Another American student sitting next to me, whispered in my ear, “I don’t know all of what they said in Chinese, but the last part was, ‘Don’t translate this for the Americans’.” The interpreter then said out loud, “Yes, we can agree to privacy.”

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

What the world needs is young dads

A couple of years ago, PETA, the radical animal welfare organization, developed a marketing campaign around a 96-year-old Indian man named Ramajit Raghav who had just entered the Guinness Book of World Records as the world’s oldest father.

However, an article in the Journal of Medical Ethics questions the ethics of Mr Raghav’s paternity. Dr Kevin R Smith, of Aberdeen University, in Scotland, points out that the older the father, the higher the rate of birth defects. With more and more men choosing to marry and have children later in life, additional disabled children could eventually lead to a significant burden on the economy and might even decrease the evolutionary fitness of the human race. This makes the age of paternity a serious ethical problem, he says.

He proposes four solutions:  health education to promote earlier fatherhood, incentives for young sperm donors and state-supported universal sperm banking, and eventually human germline modification (ie, eugenics). Dr Smith favours sperm banking. He envisages a society in which 18-year-olds will be asked to bank their sperm in preparation for future fatherhood via artificial insemination.

 Ideally, therefore, sperm could be taken (on a voluntary basis) from all young men, with AI becoming the norm for procreation. To be successful this would require state-funded infrastructure support, along with educational/publicity approaches to encourage young men to participate. If this form of society-wide sperm banking were to be widely adopted, and repeated throughout successive generations, it would have marked benefits for the human gene pool over the long term. This approach may appear radical or intuitively unwelcome to some, in that it would entail a wholescale move away from natural conception.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

Why Facebook

Three white chicken eggs with smiley faces drawn on them peer out at me from a Facebook ad. (Notably, a Facebook ad forwarded to a listserv by a young woman in college, not one that popped up in my own middle-aged Facebook feed.) One of the smiling eggs exclaims, “Donate Me and Help Make a Family!”

Fifteen or twenty years ago, this ad would have made little sense. Donate a chicken egg to create a family? But in today’s brave new reproductive world, where in-vitro fertilization, commercial surrogacy, and sperm and egg donation are no longer obscure medical secrets but commonplace knowledge, it’s fairly obvious to most people viewing this ad that it is targeted at young women, encouraging them to “donate” their ova.

I put the word “donate” in quotes above because unlike kidneys, ova are not usually “donated” in this country. While it is illegal to offer economic compensation to people for other sorts of organ donation (due, rightfully, to the bioethical concern that this will create a market for human organs, and impoverished people will be unequally coerced into selling their body parts), getting paid for giving up your ova (and sperm) is perfectly legal in the U.S.

But why is it particularly worrisome that ads for ova donation have made it onto personalized Facebook feeds?

The Commodification of Women’s Bodies: Economic Coercion

Back when the only egg donation ads I saw were in the hallways of the Ivy League medical school in which I teach, I was equally concerned. Whether on digital or brick-and-mortar walls, ova donation ads make clear that women’s bodies and body parts are commodities to be bought and sold.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

In the Journals, April 2015 – Part I by Elizabeth Lewis

Here is the first installment of our coverage of April journal articles. Enjoy!

Critical Public Health

The Transitional Dynamics of Caloric Ecosystems: Changes in the Food Supply Around the World
Sanjay Basu

Changes to the global food supply have been characterized by greater availability of edible oils, sweeteners, and meats – a profound ‘nutrition transition’ associated with rising obesity, type 2 diabetes, and cardiovascular disease. Through an analysis of three longitudinal databases of food supply, sales, and economics across the period 1961–2010, we observed that the change in global food supply has been characterized by a dramatic rise in pig meat consumption in China and poultry consumption in North America. These changes have not been experienced by all rapidly developing countries, and are not well explained by changes in income. The changes in food supply include divergence among otherwise similar neighboring countries, suggesting that the changes in food supply are not an inevitable result of economic development. Furthermore, we observed that the nutrition transition does not merely involve an adoption of ‘Western’ diets universally, but can also include an increase in the supply of edible oils that are uncommon in Western countries. Much of the increase in sales of sugar-sweetened beverages and packaged foods is attributable to a handful of multinational corporations, but typically from products distributed through domestic production systems rather than foreign importation. While North America and Latin America continued to have high sugar-sweetened beverage and packaged food sales in recent years, Eastern Europe and the Middle East have become emerging markets for these products.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

Australian Convict History Could Mean ‘Warrior Gene’ Leaves a Legacy of Crime in Our Blood

(News.com.au) – IS Australia more likely to breed criminals as a result of its historically penal gene pool? Two variations of a gene have been found to play an important role in criminal behaviour. Labelled a ‘warrior gene’ a study published in Molecular Psychiatry has found a link between two gene variations and a person’s inclination toward violent crime. The study found a variation in genes that, when activated, produced a different brain chemical reaction to other people.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

Genetic Testing For All: Is It Eugenics?

In recent weeks, there’s been talk of three types of genetic testing transitioning from targeted populations to the general public: carrier screens for recessive diseases, tests for BRCA mutations, and non-invasive prenatal testing (NIPT) to spot extra chromosomes in fetuses from DNA in the maternal bloodstream.

Are these efforts the leading edge of a new eugenics movement? It might appear that way, but I think not.

When I began providing genetic counseling 30 years ago at CareNet, a large ob/gyn practice in Schenectady, NY, few patients were candidates for testing: pregnant women of “advanced maternal age” (35+), someone with a family history of a single-gene disorder or whose ethnic background was associated with higher prevalence of a specific inherited disease. Their risks justified the cost and potential dangers of the tests.

Now the picture is rapidly changing as plummeting DNA sequencing costs and improved technologies are removing economics from the equation. It’s becoming feasible to test anyone for anything – a move towards “pan-ethnic” genetic screening that counters the “sickle-cell-is-for-blacks and cystic-fibrosis-is-for-whites” mindset.

So here’s a look at three very different types of genetic tests that are poised to make the leap to the general population. And despite new targets revealed with annotation of human genomes, some of the detection technologies themselves are decades old.

#1: CARRIER SCREENING

Population screening for carriers of single-gene diseases has been around since those for sickle cell disease and Tay-Sachs disease in the early 1970s. We learned a lot from their starkly different results. For years, labs such as Athena Diagnostics, the Baylor College of Medicine Medical Genetics Laboratories, Emory Genetics Laboratory, Ambry Genetics, GeneDx and others have added genetic tests to their rosters, which now cover hundreds of single-gene diseases, from A (Alport syndrome) to Z (Zellweger syndrome).

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

The ethics of three-person IVF

Three person IVF will prevent mitochondrial disease. Sukharevskyy Dmytro/Shutterstock

The UK parliament will soon consider making Britain the first country to allow three person IVF. The regulations are yet to be approved, but the government is currently backing moves to allow the creation of babies with DNA from three people in cases where the children are at risk of inheriting mitochondrial disease.

Objections have been raised, however, and it’s important to consider the ethical arguments for and against allowing this new procedure.

Mitochondrial disease

Mitochondria generate energy for our cells and have been compared to batteries or power stations. When people suffer from mitochondrial disease, their mitochondria don’t produce enough energy to make their cells work properly. The disease takes many forms but often affects important body parts such as the brain, liver or heart. Some mitochondrial disease is fatal and, at present, there’s no effective cure.

Mitochondrial replacement is proposed, not as a treatment for existing sufferers, but as a way of helping “at risk” parents avoid passing it on to their children. One technique (Maternal Spindle Transfer) involves removing damaged mitochondria from the mother’s egg and replacing them with healthy mitochondria from a donated egg.

Another (Pronuclear Transfer) involves removing damaged mitochondria from the parents’ embryo and replacing them with healthy mitochondria from a donated embryo, or from an embryo made using the father’s sperm and a donated egg. Any child created would be genetically linked, through mitochondrial DNA, to an egg donor, as well as to his or her main genetic parents; hence the expression “three-person IVF”.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.