Genetic Variant Connected with Obesity

by langm349 on May 7, 2017 - 4:13pm

It is well known that there is a current problem with obesity rates in America. It is also common to see a family where many of the members are overweight or obese. While an individual’s diet and activity level plays an important role in a person’s weight, a recent study has found that there may be a genetic factor involved.  Published in the journal Obesity, researchers found an association between obesity in African Americans and West Africans, and a genetic difference in the semaphorin-4D gene (SEMA4D). The SEMA4D gene is in involved in cell signaling, bone formation and the immune response in the body. Although most genomic studies on obesity have been done one people of European decent, African Americans have the highest age-adjusted rates of obesity. This study was completed by using a Genome-Wide Association Study (GWAS), which compares genomes of those that are obese and those that aren’t. This study is first of its kind because the previous studies that were done on individuals of European or Asian descent, would not of shown the SEMA4D gene variation because it isn’t present in that ethnicity.  The study examined obese and non-obese individuals in West Africa and then replicated the study in a large group of African Americans. It was found that those with the SEMA4D variant were on average 6 pounds heavier than those without the variant. Researchers hope to organize another study on the DNA sequencing of this gene in other populations, possibly discovering more genetic factors contributing to obesity.

Mjoseth, Jeannine. "2017 News Release: Study identifies African-specific genomic variant associated with obesity." National Human Genome Research Institute (NHGRI). N.p., 13 Mar. 2017. Web. 07 May 2017.



Hello langm349,

This post is very interesting. I never thought obesity would be related to genetics and thank you for making me discover that.You summarize very well the article but maybe separating your post into paragraphs would have convinced me even more to read it.

Even if obesity has a big genome component, I think that people should see the facts that choosing a good lifestyle is still what is mostly going to determine if one is obese or not. I think your post is excellent in explaining why certain people would be more affected than others–that, according to the study mentioned in the article you summarized, those who had the SEMA4D gene variation had on average 6 pounds more than the ones who did not have it. Although this is a major scientific advancement, I am scared that people might use it for the wrong reasons; that if they are obese, they will think that it is because "They were born this way". Wouldn't you agree?
Well, that was what I thought before I saw this article and the video at the end of it:
This Australian article mentions that diets can be useless when it comes to some people who are obese and that it is not a choice to become "fat". In fact, 20% of Australians cannot get rid of their obesity no matter what they try to do. Dr. Rauchberger states in the video that obesity is a genetic disease and not a lifestyle choice which contradicts exactly what my initial thought was. Yes, DNA samples of Dr. Rauchberger's patients have helped the doctor determining specific diets according to their unique DNA. It is called a personal DNA test and they are available in different Australian pharmacies. Its procedure is explained by Dr. Rauchberger as this: "When you get a personalized report, it will say based on your genetic profile, you should go on, for example, a high protein diet or it might say you should go on a low-fat diet or a diet that is rich in Mediterranean food." This also exists in Canada (there is a DNA testing centre even in Montreal!), so it is easily accessible in big cities. The audio, video, and article are so interesting and I think you should take a look!

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