Genetic Testing: What's in Our DNA?

By Colby Weber

When your parents say “Let’s go looking for genes,” you would suspect that you’re going to go clothes shopping.  However, with the sudden surge in popularity of genetic ancestry tests, this may not be the case.  
Websites such as AncestryDNA or 23andMe offer users the ability to trace their heritage back throughout the years and discover distant relatives.  In exchange, they ask that you send in an amount of cash and a saliva sample.

            
The commercials for the websites above feature excited people discovering their long-lost great grandparents or their Italian heritage.  While these stories are able to be viewed by the general public, some may find it unclear as to how else DNA tests can be used. The blurbs from the companies don’t give very much information in regard to how accurate their tests are.  In order to obtain a deeper understanding of this topic, a survey of the general public was taken.

            In a sample of five college students, three of the five said that they would be willing to do a genetic ancestry or DNA test.  20-year old Aiden Fogarty said “I wouldn’t really care, I already know who I am and what my genetics are, but if somebody else wanted to I wouldn’t mind.”

            Other students weren’t quite as willing to take one of the tests.  “I’d say hell no, a solid hell no,” said 21-year old Garrett McFarland.  “There’s no reason.  If you’re white, you generally know where you’re from.  You don’t send your DNA into the internet, that’s a stupid concept. I’m German, Dutch, and Irish.  I know that, so I’m good to go.”

            While enthusiasm for the tests varied from one person to the next, none of the students who were sampled were willing to pay for the tests themselves. Despite not being willing to pay for the test, 20-year old Nick Schindler said “I would probably pay nothing, but if someone gifted it to me I would do it.”  In other words, money may have been a significant obstacle toward the subjects taking the test.  While this could not be guaranteed for every person, a college student’s typical lack of funds may have been a factor in this sample’s answers.

            The sample seemed to have a variety of ideas and applications for the uses of genetic testing.  19-year old Hunter Orthmann had so many come to mind that he could barely count them all. “Oh boy, there’s such a big spectrum,” he said.  “Me personally, maybe I’d do one to see if my kids were at risk for some condition, or if I would be at risk for something.  Maybe someday I would be interested in the genealogy aspect and how you could trace back ancestors or something.”

            Consumer confidence in the accuracy of the tests seemed to be reasonably high, but it wasn’t consistent among all subjects.  “I think they’re fairly accurate, I would guess they’re 80% accurate, not 100%.  I don’t know which brand is better, I haven’t done any research on them,” said Schindler. On the other hand, 19-year old Jacob Sly wasn’t as convinced.  “I saw a thing recently that says that they’re not that accurate,” he said.

            Two of the five people sampled had some kind of experience with DNA testing. My uncle bought a DNA test kit for two of my aunts to prove that they weren’t as Irish as they said they were,” explained Schindler.  “He was right.”

            Hunter Orthmann had his own DNA tested during a classroom experience.  In his biology class, they examined the lactose-intolerance gene and the TAS2R38 gene.  While the TAS2R38 gene doesn’t serve a practical purpose, those who possess the dominant form of it (which takes over if present) can taste a bitter chemical.  Those who possess the recessive variety of this gene are unable to.  The professor asked his class if they were lactose intolerant, and then they compared the expected allele frequencies for lactose intolerance with the results from their in-class activity.

            According to University of Northern Iowa biology professor Nilda Rodriguez, there are several steps involved in genetic testing.  “Once you’ve obtained a sample, you can use a kit to isolate the DNA,” she said.  “DNA is a long string of bases, which consist of A, C, T, and G.  Three of these can form a sequence which create different combinations.  We can then read that information and find out what kinds of proteins are being produced. There’s DNA and RNA, and your skin and blood cells have the same information or DNA.  However, what you express in each cell is different, which is where the RNA comes in.  You’re you, but there are different expressions of you, like the you as a student or you as a son or daughter.  Your cells do the same thing.”

Scientists can use your DNA for a wide variety of applications.

            Once the DNA has been isolated, there are several different applications for DNA testing besides ancestry tracing.  Dr. Rodriguez says that one of the primary uses is for diagnostics.  For example, a baby can be tested for diseases such as Cystic fibrosis.  This is possible because scientists know the sequences which your DNA is supposed to have, and when a particular variation appears, they can link it to certain diseases. 

            Forensics is another major aspect of genetic testing.  “We’ve saved people who were going to be wrongly convicted,” said Rodriguez.  “One guy was in court for killing his step-daughter, and the genetic tests said that there was a 99% chance that it was him.  When combined with physical evidence, DNA testing can serve as a very strong indication of guilt.”

            Dr. Rodriguez finds one of the most promising spin-offs of the testing to be looking for mutations in tumors.  In a new phase of cancer treatment, doctors can examine the specific mutations that a patient’s tumor has undergone.  By looking at the DNA of the mutated tumors, health professionals can figure out if their patient’s cancer will respond to chemotherapy.  A more targeted therapy treatment can use your immune system to make antibodies which fight the cancer but not your other cells.  The downside to this type of treatment is that mutations in your DNA can make it so the immune system antibodies don’t work.

Occasionally, the uses of genetic testing can intersect. Within a report by The Washington Post, the “Golden State Killer” was caught using DNA from a genealogy test.  While DNA testing was not as prevalent then as it is now, 40 years later they were able to track down the killer, Joseph James DeAngelo. While they did have his DNA, only a small amount of witnesses had gotten a clear look at his face.

DNA testing plays a significant role in forensics, where it can be used as evidence for a crime.

            DNA testing has begun to appear in the public eye, but it has also made its way into politics.  In an article by The Boston Globe, our current president Donald Trump accused Senator Elizabeth Warren of lying about her Native American heritage.  In his attacks, he has called her “Pocahontas” and claimed that he will pay one million dollars to any charity she wishes if she takes the test. Despite Trump’s words, Warren was defensive about where she came from.

After hearing his claims, Warren decided to submit her DNA for analysis.  After the results were received, she released them to the public.  Within their contents, it’s stated that Warren is “between 1/64th and 1/1,024 Native American.”  As of recently, Trump has not paid Warren after the results have been revealed.

While DNA testing can be used for a wide variety of applications, the accuracy of the tests is still up for debate.  It is also possible that different types of DNA tests will give you various results and levels of accuracy.  “I’ve heard that some tests give more information or look for more genes than others,” said Dr. Rodriguez.  “How accurate that could be is anyone’s guess.  I would have to read about the protocol, so I’ll let people be the judge.  Scientists will have a rigorous protocol to control what they’re looking for when it comes to this type of testing.  Once you submit the saliva, I don’t know who controls that.  Things can get degraded in the lab.  You must manage each step properly.”