The Genetics of Marfan Syndrome

The trait I am testing for is Marfan Sydrome, an inherited genetic disease caused by a mutation in the FBN1 gene. While not very common, only occurring in around one in five thousand people (NIH), Marfan’s main symptoms are elongated limbs, worsened vision and heart issues. Only one gene is known to be the cause, and it can result from a change in any of the many alleles within the gene.

Marfan affects the production of fibrillin, a compound key to the extracelluar matrix and skeletal and muscular development¹. The condition causes the afflicted to be taller than average, along with having thin arms and legs and possible heart issues. The above average height of those with Marfan can be very beneficial for athletes, especially basketball and volleyball players. Famous atheletes with Marfan include Olympic medalist Flo Hyman and basketball player Isaiah Austin. As the mutation affects the above developments, it makes sense that those carrying it have thinner, weaker muscles due to a less strong extracelluar matrix which provides support around cells through a compound called fibrillin. Marfan leads to decreased fibrillin production, and thus less strength and elacticity in tendons and muscles. This leads to those with Marfan tending to have longer, slimmer limbs and aorta issues in the heart.

Testing for Marfan would more than likely be done to test for the likelihood of the disease in offspring. The condition is not always obvious, depending on the severity of symptoms. A SNP-ChiP is best recommended, as this test can encompass the entire gene and detect any and all SNPs which have mutated, leading to the affliction². There is no specific allele or SNP known as the cause, many different ones from FBN1 have been seen to cause Marfan³. This test can run anywhere from $200-$2000, depending on insurance and the laboratory running the test. There is a very strong connection between these mutations and the disease, as over a thousand alleles have been tied to it⁴ and if you have the mutation you will demonstrably have the disease. Getting a test done is most effective to determine risk in newborns to see if they will later develop symptoms. The risk of inheritance is fifty percent if one parent has the condition as it is autosomal dominant and those who carry the mutation are at a one hundred percent risk of developing symptoms.

Testing is not necessarily needed for this condition, but may be beneficial. Those who have any of the mutations will in many cases show symptoms and thus not need testing. Parents, however, can use testing to segregate eggs which do not carry a mutation and selectively breed children through invitro fertilization. The ethics around this are murky and can cause controversy. Adults with the condition commonly know they carry it and do not need to give up genetic information to a company just to discover they have a mutated allele they already knew about. From a scientific point of view, testing is not commonly needed. Those with symptoms should strongly consider getting tested. The main possible benefit would be that a positive would indicate possible heart issues, and further testing could be done. Getting a test done could also be beneficial for those without symptoms, as they may not visibly show it but could have Marfan and potentially develop complications. There are few ethical concerns around this kind of testing, with the only main exception being around in-vitro fertilization and selective breeding.

Family history plays a large part into having Marfan. If one parent has it, the child will have a fifty percent chance of having it as it is an autosomal dominant condition. Marfan is only inherited directly from an afflicted parent. One has a roughly one in twenty thousand chance of randomly developing it. There are no needed environmental adjustments needed if the test is positive however, as the disease is not affected by the environment. A positive or negative result from the test is only significant for a child who has not yet developed symptoms or for an adult with onlt one symptom. As Marfan is untreatable, in this case the parents could try to mitigate symptoms, but they cannot be fully treated. Adults who show as positive could also get screened for heart issues which are commonly tied to Marfan.

References

1. NIH. (2019, November 12). Marfan Syndrome. Retrieved from https://www.nhlbi.nih.gov/health-topics/marfan-syndrome#.

2. Singh et al. (2015). Single-copy gene based 50 K SNP chip for genetic studies and molecular breeding in rice. Scientific Reports, 5(1). doi: 10.1038/srep11600

3. Mayo Clinic. (n.d.). Test ID: FBN1B FBN1 Full Gene Sequence, Varies. Retrieved from https://www.mayocliniclabs.com/test-catalog/Clinical and Interpretive/64514.

4. SNPedia. (2018, December 8). Marfan syndrome. Retrieved from https://www.snpedia.com/index.php/Marfan_syndrome.

Clarke Central Outreach Reflection

For my outreach, I went to Clarke Central High School to help with obtaining the high school samples for the antibiotic resistance project. We spent a class period working with the students on the samples.

I was given roughly a third of the class as my group, along with their respective sleeves of Petri dishes. We worked on sorting them by density of growth and photographing the best samples. Next we restored all the trays to the original order of strength of antibiotic and set number. Working with these students was a very positive experience. I was very surprised by how bright and enthusiastic my group was about the project. It was a much smoother and more positive experience than I expected.

The thing that most surprised me was how much the high schoolers looked up to us, the college kids. Although I am only one grade level above most of the guys who were in my group, they seemed to view me as some kind of knowledgeable elder. While I could not answer all the questions they had about science, they did ask me many thoughtful, smart questions about what college was like and advice on the admissions process. I made a close connection with two of the students and we had an extended conversation about life at UGA. Since then, we have talked several times and I’ve been help to help them through the admissions process. Through the outreach, I gained two new friends and learned a lot about myself having the privilege of attending UGA and also about those in the community we call home.

Sadly I do not have any photos. We were too caught up in Petri dishes and college advice that I forgot to take some!

Climate Simulation

Participating in this exercise, I felt that I gained a better understanding of the urgency of the climate change issue. My group as a whole began to see more of the importance as time went on and became more and more open to the stances and ideas of the other groups. We also went from an “us-versus-them” mindset to that of a group working towards a goal.

We, the United States, started with a very isolationist and protective stance. On Day 2, we realized that this approach was not going to get us very far and some of the other groups were taking the place as frontrunner which we should have held. Watching the other teams seemingly make all this progress without us and in gaining more information about the issue, we became more open.

I do think that emissions need to be cut in order to slow global warming. This is a key critical issue for us and for the future generations of earth. There are many obstacles in the way, though, chiefly being the hefty financial burden needing to be undertaken by developed countries to help foot the bill and the partisan disagreements between nations over how to best handle solving the problem. If the nations of the world could be more generous financially and open minded, tackling climate change would not be hard at all.

In the United States, we most importantly needed to bring the issue into education. Educated citizens have a strong correlation with supporting the fight against global warming, and this only grows as you filter down by age. A massive effort must be undertaken by America as a whole to raise awareness and work towards change.

Watershed Reflection

Here, we can see a storm water pond on East Campus. It is decently sized and can hold quite a large volume of water, although it is not near full capacity in the photo. This pond is something we as the UGA and Athens communities should care about as it helps to reduce flood damage and retain excess precipitation.

One thing that really strikes me as interesting is just how shallow it is. We have had lots of rainfall lately in large bursts and while it has not exactly been pouring everyday, I would expect a higher water level from the rainfall.

To the average person walking around campus, this seems like just another pond, maybe with some fish. This made the gears in my mind begin to turn: what would happen if it was not there? How would campus be different? Would we not be able to drive on some roads during heavy rainfall? Would students not be able to attend class? Would deliveries not get made on time? As an economics major, the simple idea of a small disruption to the ecosystem has me thinking about all the ripple effects in our daily lives not having a storm water pond could cause.

When I see this photo, I feel a sense of security knowing that we as a group can always continue our battle against Mother Nature. I think this picture is about the value we place on simple things like storm ponds that help us, quietly and behind the scenes, live our daily lives.

Joe Berman

I’ve taken Honors Bio, Honors Chem, AP Psychology, and Honors and AP Physics. I preferred Psychology, as the nature of the material was most interesting to me in that I learned many things about the world around us that are actually applicable to daily life.

From this course, I would like to gain a better understanding of biology and of the environment around me. The world is fascinating and I would love to have an informed perspective.

The outreach at Clarke Central appeals to me most as it entails working with the local community. I have done several environmental projects back in Augusta and put my knowledge to good use. I think that students on campus would definitely become more interested in these issues if they were aware of topics such as the clean water they drink or well preserved nature areas they walk through.

I believe I will gain a better grasp at working with the public sector through the organization of the projects we complete in this class. Also, I look forward to learning about the specific environmental needs of the Athens area.

Of interest for me is learning about waterways and the water system and what I can do to maintain a healthy ecosystem. I am also interested in learning about microbiology, and the real world applications of it.