Tuesday, April 3, 2012

How Useful Is Whole Genome Sequencing to Predict Disease?

                This article presents the findings of a study published online April 2 in Science Translational Medicine that full genome sequencing might not even be so helpful in predicting disease, as few diseases have strong enough genetic components to make it a reliable way to assess individual risk. The study’s co-author,  Bert Vogelstein, director of the Ludwig Center for Cancer Genetics and Therapeutics at Johns Hopkins University, said that most common diseases, including heart disease and stroke, do not result from a single-point mutation, or even a combination of them. These kinds of diseases also involve one's own lifestyle and environmental exposures. Vogelstein and his colleagues set up an experiment that examined genetic and health data from large existing registries of tens of thousands of identical twins. They looked for 24 common health issues, including some cancers, along with autoimmune, heart and neurological diseases. Though we do not yet have a perfectly clear picture of all how all of these conditions could potentially spear in genetics, the researchers figured out a model that acted as if we did already have that knowledge for the purpose of testing “the upper boundaries” of what we might be able to learn from the genome alone. Still, most people will wind up getting a “negative” (meaning low risk) result in terms of their risk for most diseases. However, for about half of the diseases most of individuals from the registries who would have received a "low-risk" result from a whole-genome sequence would have ended up getting one of these diseases anyway, meaning that this testing wasn’t going to help much. Nonetheless, they found promising results in studying twins’ chance for Alzheimer’s: those in the study whose genomes showed a low risk for Alzheimer's, for example, did have about a 12 percent ( much, much smaller) risk than that of the general population. They also note that one of the keys to improving disease risk prediction will instead be to collect even more information regarding nongenetic factors because most disease contributor factors are nongenetic anyway.
                Clearly this study is very relevant to society and all of our lives. People are really interested in disease prevention, and they always will be. People do often think that genetic factors can give solid readings of their chances for contracting diseases, but this study shows that studying the human genome really doesn’t help much for what it’s worth and probably won’t in the future because these diseases are often due to lifestyle differences or external exposures rather than destined to show up in an individual because of his or her genetic makeup. Furthermore, the researchers note that by better understanding the limitations of genome-wide sequencing, researchers and policymakers might be better able to direct funding and efforts to areas, such as Alzheimer's disease, where a person's genetic profile might actually have an effect on their likelihood of getting the disease.
                This article was quite well done, and I think this study is particularly relevant in terms of what  people need and want in our society, as well as the fact that it brings our idealism about uncovering the key to the eradication of all terrible diseases down to earth: we simply don’t have the science yet, and even when we do, it’s likely it will only help in a pointed area. I thought the discussion about the Alzheimer’s risk was particularly important, though I would have liked to see more numbers for that. Also, I think the writer could have gone further into detail about other diseases besides Alzheimer’s for which full genome testing would actually be useful and described the model that the scientists developed to test high risk or low risk: it wasn’t technically necessary, but the nebulousness , made it harder to conceptualize.

ARTICLE LINK:
http://www.scientificamerican.com/article.cfm?id=whole-genome-sequencing-predict-disease&page=2

3 comments:

  1. Elizabeth Cory did a great job summarizing the article, “How Useful is Whole Genome Sequencing to Predict Disease?” by Katherine Harmon. Elizabeth clearly stated why genome sequencing is seen as risky and not helpful. She wrote about the experiment set up by Bert Vogelstein, director of the Ludwig Center for Cancer Genetics and Therapeutics at Johns Hopkins University, and clearly explained the outcome. Elizabeth also did a great job connecting this article to our society. People are extremely interested in preventing diseases; they often believe that genetic factors are able to tell people about their chances for contracting diseases. After connecting this article to everyday life, Elizabeth makes it clear that this study shows that studying the human genome is not useful. Having diseases are most likely due to other factors, such as diet, exposures to carcinogens, and family history.
    Although Elizabeth nicely summarized the article and connected it to our society, she could have improved it by explaining what genome sequence is, and how it works. Also, she could have researched about what other scientists think about genome sequencing. She could have wrote about the opposing side of this topic (why some scientists believe that genome sequencing is helpful).
    Before reading this article and Elizabeth’s review, I did know what genome sequencing is, but I did not know why it is seen as not useful. However, now I undertstand the negative side to genome sequencing. Diseases do not take place in an individual due to his or her genetic makeup. I learned that diseases often occur due to one’s lifestyle or external exposures.

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  2. I feel that Elizabeth did good work reviewing this article, "How Useful is While Genome Sequencing to Predict Disease?". One of the main points of the article, Elizabeth says, that genome sequencing is too risky to be an effective move to help a patient suffering from diseases such as heart disease and strokes. The experiment she described was easy to read and important to me and I'm sure a lot of others, considering so many people suffer from heart disease and stroke. While it would be nice to see that this genome sequencing is effective, at least there were results and we have realized it is not really an option in medicine. I also thought she did a decent job of using simple language to make it easier on the eyes of the reader.

    To improve this review, though, I propose that genome sequence be described a bit better, because as it's written right now, we basically get no information on what it actually is. The process behind testing genome sequence would've been helpful as well.

    I found this review to be a easy read, and I think Elizabeth did an excellent job summarizing. She did an amazing job of showing how it relates to us as humans and I was glad to know that, even though the tests were not positive when experimenting genome sequencing on patients with certain diseases, studies are being done to improve our understanding of such common diseases.

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  3. I think my classmate, Elizabeth Cory, did a great job reviewing the article, "How Useful is Whole Genome Sequencing to Predict Disease." Elizabeth did a good job summarizing the experiment carried out by Bert Vogelstein, the director of the Ludwig Center for Cancer Genetics and Therapeutics at John Hopkins University. She clearly explained the experimental procedure and I was able to follow for the most part. Elizabeth also mentioned why this experiment is significant: in our modern society, disease prevention is one of the top priorities in healthcare. I also liked how Elizabeth's review incorporated some vocabulary that we had recently learned about, such as point mutations.
    The one thing I will criticize is the lack of an explanation of what genome sequencing is. Only after googling the definition was the article a bit more clearer to me. She could have also mentioned why genome sequencing had been so popular and never been challenged before.
    I found this article interesting because I always had the notion that a lot of diseases result from genetic mutations, however, this argument contradicts that. I think this discovery is helpful for scientists who will approach pathology with a new outlook, focusing on external factors in stead of genomes.

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