Tag Archive: bioethics


Ok, let’s start off with the basics:

Parkinson’s disease is a neurological disorder where nerve cells that make dopamine are destroyed. Dopamine is an important neurotransmitter and without it, nerve cells are unable to properly send messages to other parts of the body. Eventually, the destruction of dopamine-producing cells leads to a loss of muscle function that gets worse over time. The typical symptoms of Parkinson’s are shaking and difficulty with walking, movement, and muscle coordination.  Unfortunately, not a lot is known about why these nerve cells waste away in the first place.

In gene therapy, a gene variant is used to alter the function of a cell or an organ. The way that genes are transferred into cells is pretty interesting: the gene is put into an inert virus, which is then injected into the target cell to deliver the gene.

Now, a new large-scale study suggests that a type of gene therapy (called NLX-P101) may be able to improve Parkinson’s symptoms. The gene that was targeted is called GAD (stands for glutamic acid decarboxylase). This gene produces a chemical called GABA (stands for Gamma-aminobutyric acid), which is a neurotransmitter than inhibits the excessive firing of neurons seen among Parkinson’s patients. From an interview in ScienceDaily with one of the researchers, Dr. Matthew During:

“In Parkinson’s disease, not only do patients lose many dopamine-producing brain cells, but they also develop substantial reductions in the activity and amount of GABA in their brains. This causes a dysfunction in brain circuitry responsible for coordinating movement,” explains Dr. During.

So, what they’ve done is inject a fully-functioning GAD gene into the brains of Parkinson’s patients. Those that were injected showed substantial improvement compared to individuals that did not receive the treatment.  

References

LeWitt, P.A. et al. (2011). AAV2-GAD gene therapy for advanced Parkinson’s disease: a double-blind, sham-surgery controlled, randomised trial. Lancet Neurology in press.

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The FDA held a meeting on March 8th and 9th about direct-to-consumer (DTC) genetic testing. According to the FDA’s executive summary, DTC is:

…clinical genetic tests that are marketed directly to consumers (DTC clinical genetic tests), where a consumer can order tests and receive test results without the involvement of a clinician.

As Dan Vorhaus of the Genomics Law Report describes it, the main issue of the meeting was to decide how (and if) the FDA will regulate DTC genetic tests. There were really two perspectives:

1. Those who oppose DTC genetic testing worry that incorrect or misinterpreted tests could produce harmful outcomes, and they even questioned whether anything of value is actually gained from the tests in the first place.

2. Those who support DTC genetic testing argue that the information empowered patients to explore their “genetic selves” without any ill effects.

The meeting will sum up with recommendations for the FDA from the Molecular and Clinical Genetics Panel (MCGP), which is an FDA committee that “reviews and evaluates data concerning the safety and effectiveness of marketed and investigational in vitro devices for use in clinical laboratory medicine including clinical and molecular genetics and makes appropriate recommendations to the Commissioner of Food and Drugs.” Vorhaus suspects that the MCGP will recommend:

that clinical (as defined by the FDA, which is itself a separate issue) direct-to-consumer genetic testing, when offered without a requirement that a clinician participate in the ordering, receipt and interpretation of the test, be removed from the marketplace. At least for the time being.

Our keynote speaker, John Hawks, blogs about this issue and considers himself a “genetic libertarian.” He describes his position:

I believe that I have a fundamental right to my own biological information. What I mean is that, if anybody has biological information about me, I should be able to access and use it. Additionally, I think it is immoral for anyone to charge me excessive rates to access my own information. So that’s where I’m coming from. I’m a genetic libertarian. 

For more info see the FDA’s website for the event.

What do you think about DTC genetic testing? Do you think it’s a good idea? How much regulation (if any) should be provided by government agencies?

Continuing with our exploration of the vignettes in Science’s 10th anniversary celebration of the human genome project, we run across an interview with Eric Green, who just recently became the director of the National Human Genome Research Institute. As with all of these pieces, there’s lots of interesting stuff here. A couple of highlights from the interview:

Q: Why did you set 2020 for when genomics will begin affecting health care? Why is it going to take so long?

Eric Green: When we talk to people who have a historic view of medical advances, they have pointed out that truly changing medical care takes a substantial amount of time. Often decades. And I’ve grown sensitive to the criticisms of genomics by some who believe that since 2003, when the genome project ended, we haven’t sufficiently improved human health 7 years later. So part of the reason is just to be a little bit more realistic and a little more cautious.  

Q: Where are you hoping we will be by 2020?

Eric Green: I’m hoping that by 2020 we will have this incredible mountain of information about how genetic variants play a role in disease, that it will just provide an entirely new venue for really thinking about how to both predict disease, maybe prevent disease, and certainly treat disease.

Notice that Dr. Green seems pretty confident in our ability to use genomics to predict and treat disease, but puts a “maybe” in front of prevention.

References

Kaiser, J., Green, E. (2011). The genome project: what will it do as a teenager? Science 331: 660.

We’re starting to go through some of the interesting vignettes in Science’s 10th anniversary celebration of the human genome project. One of these papers takes a realistic view of how genomic research has benefited human health over the past 10 years. A few areas that the authors touch on:

1. Identifying risk:  The predictive power of most genetic variants associated with diseases is not very high. This means that the potential benefits of separating patients even into gross categories such as “high” and “low” risk based on the presence/absence of disease-risk genes are in many cases outweighed by the cost of potentially misclassifying (and thus mistreating) them.

2. The difficulty of changing behavior: When someone is told they are at a genetically higher risk of developing a particular disease, there is really no evidence to indicate that they change their dietary or exercise habits (see also this post on the blog). Altering an individual’s environment (regardless of the presence/absence of disease-risk genes) is probably a better, and more lasting, way of convincing them to be less lazy, or to eat better and not smoke.    

3. False hope: Scientists and the press are both responsible for creating false hopes for genomic research in human health.

The authors do suggest that the following are realistic expectations:

1. The genes responsible for most Mendelian disorders will be identified. This will permit quick diagnoses, particularly for diseases that are caused by a single gene. 

2. Pharmacogenomics (the study of the influence of genetic variation on drug response) will enhance the safety and efficacy of treatments. However, because a lot of variability in drug response is tied to non-genetic factors, we can’t expect genomics to completely solve this issue.    

They make the interesting suggestion that because most mortality in high-income countries results from things like smoking, sedentary behavior, and excessive food and alcohol consumption, the diseases associated with these factors are best (or at least as effectively) researched via the social and behavioral sciences (i.e., how do we change these behaviors?) rather than through genomics (i.e., how do we identify individuals at genetic risk for these diseases?).  

References

Evans, J.P., Meslin, E.M., Marteau, T.M., Caufield, T. (2011). Deflating the genomic bubble. Science 331: 861-862.

UPDATE 2.23.2011. Dr. Hawks blogs about this issue here.

We’ve talked about SNPs (single nucleotide polymorphisms) before on the blog. These are mutations in single bases along the DNA molecule. Because it has been found that some SNPs are associated with particular diseases, geneticists scan genomes to identify SNPs that may either explain a disease or at least identify individuals that may be at risk for a disease. As described in a recent report in Reuters, one unintended consequence of these genome scans has been the identification of incest. As many of you know, the development of abnormalities in offspring is more common in incestuous (i.e., mating with a close relative–how “close” is “close” varies by culture)  matings. Because closely related individuals share a greater proportion of their genes, the chances are greater that deleterious recessive genes (genes that are only expressed when an individual has two copies, one from either parent) will pair up in their offspring and cause problems.

Although this new information of course has important legal implications, in most cases the physicians were already aware of the incestuous relationship.

References

Schaaf, C.P., Scott, D.A., Wiszniewska, J., Beaudet, A.L. (2011). Identification of incestuous parental relationships by SNP-based DNA microarrays. Lancet 377: 555-556.

Can (and should) genes be private?

Matthew Herper of Forbes.com has posted an interview with Misha Angrist, who is the author of “Here is a Human Being: At the Dawn of Personal Genomics.” The jumping off point here is that Angrist participated in an experiment where not only was his genome sequenced, but it was made public. From there, the interview touches on three things:

1. It’s really cool to be able to see your own sequence data right in front of you.

2.  In the not-too-distant future, everyone is going to go through full-genome sequencing.

3. Can, and should, genome data be kept private and anonymous?

Angrist also provides a guest post on the blog Genetic Future in response to a paper in Trends in Genetics. The paper outlines the arguments for, and against, returning genetic data to research participants. The authors take the view that if (and only if) something “life threatening and actionable” is found within an individual’s genome, researchers have the moral obligation to say something but full disclosure is not recommended because it puts full sequence data in the hands of research participants. You can read Angrist’s guest post, but his stance is revealed by a great quote from the Forbes.com interview: “Genetics is too important to be left to geneticists.”

Do you think that complete sequencing data should be fully disclosed to research participants? Would you make your genome public? For more discussion and to participate in a poll, check out The personal genome project, genetic privacy, personal medicine on the blog.

References

Angrist, M. (2010). Here is a Human Being: At the Dawn of Personal Genomics. Harper: New York.

Brendenoord, A.L., Kroes, H.Y., Cuppen, C., Parker, M., van Delden, J.J.M. (2011). Disclosure of individual genetic data to research participants: the debate reconsidered. Trends in Genetics 27: 41-47.

An interesting story by Osagie K. Obasogie of the Huffington Post discusses proposals to lower the bar for collecting and keeping the DNA samples of individuals arrested (but, as we shall see, not necessarily convicted) of crimes. For example, David Paterson, the Govenor of New York, has suggested a law whereby the state DNA database would include not only individuals arrested for felonies but also some individuals that were convicted of misdemeanors. Another example:

[T]he United States House of Representatives recently passed legislation that creates millions of dollars in incentives to encourage states to mandate taking DNA samples from individuals arrested for (but not necessarily charged with or convicted of) certain crimes. This provision (H.R. 4614) is part of the Katie Sepich Enhanced DNA Collection Act of 2010, named after the tragic rape and murder of a young New Mexico woman. The bill provides a 5% bonus in federal money granted to states under a justice assistance program for “minimum DNA collection,” which includes taking DNA samples from felony arrestees of specified major crimes. A 10% bonus would be given to states that partake in “enhanced” collection, which includes the extra step of taking DNA from those arrested for specified lesser crimes. 

As Obasogie points out, this may lead to a situation where the DNA of innocent people is stored along with that of the guilty. For more information on this and other bioethical issues, visit the Center for Genetics and Society

What do you think of the government holding on to the private and sensitive information that is potentially held in an individual’s DNA profile? Does this impinge on civil liberties? 

UPDATE 2.1.2011. A law that will expand the collection of DNA in North Carolina will go into effect on Feb. 2, 2011. Read more at WUNC.

Gene doping

Doping among elite athletes may have reached a new level…

As laid out by Discovery News, some athletes are trying to “turn on molecular switches inside the body’s own DNA to produce more oxygen-carrying blood or creating bigger muscle cells.” In essence, people are trying to make the genes that code for oxygen carrying capacity or muscle cell development work harder and faster. Scientists are in the process of developing a test for this sort of thing that may be in use before the 2012 Olympic Games in London.

One of the more interesting aspects of this story is the potential side effects. For example, mice that were genetically modified to produce more red blood cells (whose major job is to carry oxygen throughout the body) actually died of stroke because too many cells were being created. In another example, experts suspect that modifying the genes that code for muscle cell creation may only work on part of the body–you could have a super buff right arm and a normal left arm, for instance.

Here is an interesting video conversation with Alondra Nelson, one of our panelists for this year’s event, about how people construct their racial identity in the age of genomics.

Last month, Diane Rehm of NPR had an interesting dicussion on DNA sequencing and personal genomics (you can listen to the 51-minute show in its entirety here). The completion of the human genome project in 2003 held the promise of using an individual’s genetic information to optimize their treatment. One example that the show uses is that of Google co-founder Sergey Brin, who has discovered that he possesses a mutation in his LRRK2 gene that may increase the likelihood of him developing Parkinson’s disease later in life. Nevertheless, the program’s guests demonstrate that there are still significant hurdles to truly effective genetic-based “personalized medicine.” A couple of interesting points from the show:

1. The cost of genome sequencing has declined greatly over the past decade or so. Some companies, like 23andMe (which was founded by Brin’s wife Anne Wojcicki) will sequence parts of your genome for about $500. For those of you interested in getting your entire genome (all 3 billion base pairs) sequenced, you can, with the consent of your doctor, send samples to companies like Illumina for the bargain price of about $20,000 (if you think that’s a bit pricey, consider that a decade ago it would have cost you about $1,000,000).

2. One of the guests, Dr. Arthur Caplan, provides examples of how people can react to genetic information. The most striking is the case where a father wanted to have his 13-year-old daughter tested for mutations associated with breast cancer risk (the family had a history of the disease). The father stated that if his daughter tested positive for one or more of the mutations, he would have her breast buds surgically removed to make sure that she did not suffer the same fate as other family members (Dr. Caplan does not tell us what ultimately happened with this case). One of the points that Dr. Caplan makes with this and other examples is that, although genetic screening can provide useful information, external environmental factors interact with genes in very complex ways, which currently makes it very difficult to assess an individual’s chances of developing conditions like cancer based simply on the presence or absence of particular genetic mutations (but see Personalized medicine in 10 years?).

3. All three of the guests discuss the issues surrounding genetic privacy. Once you submit samples for genetic sequencing, how can you be sure that your information will be kept private? If it is not kept private, what can it be used for? The importance of this issue is revealed by the signing of the Genetic Information Non-discrimination Act (GINA) by president Bush in 2008, which prevents discrimination based on genetic information when it comes to insurance and/or employment.  

Check out the show and hit us up with your comments: Would you want your genome to be publicly available? Would you even want to know what your genome looked like? If you had the information, what would you do with it?

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