College College Biology and Chemistry TSS

Genes: The Stories They Tell

If you could find out how you might die, would you?

Genes can tell us a lot about ourselves.

And to many, that’s a terrifying concept. If a freshman in college sequences her genome in its entirety, she might find out that she is positive for the BRCA2 mutation present in breast cancer patients. That means her likelihood of developing breast cancer when she ages is about 87% percent. Would she, an eighteen-year-old, really want to know that she might get cancer at thirty-five years old?

On the other hand, imagine that she is a newborn receiving this same genetic test that will find her BRCA2 mutation. Doctors already perform genetic screens in newborns for a number of disorders such as cystic fibrosis and sickle cell disease (1). Early intervention can help avoid lifetime disability and reduce pain or symptoms (2).  While the BRCA2 mutation is not commonly on the list of genetic disorders in these newborn screens, it causes a condition called Fanconi Anemia that is treatable in newborns but only certifiably diagnosed through genetic testing. In this case, our patient may not have even survived until the age of 18 to worry about her potential of getting breast cancer if her Fanconi Anemia had not been treated when she was a newborn. So what is better — sequencing a newborn’s genome in order to find mutations for treatable neonatal conditions that might lead to adult onset diseases or not sequencing the genome at all and risking an early death as a newborn?

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Photo by Luma Pimentel on Unsplash

These were the questions debated during my research internship this summer. The truth is, real life scenarios are even more complicated than the hypothetical I described above. Breast cancer can be avoided through preventative surgery such as removing one’s ovaries (3), so some may argue that early knowledge could potentially save this woman’s life. However, what if her genes showed mutations pointing to Parkinson’s or Alzheimer’s or other non-curable diseases? Furthermore, when an infant is sequenced he or she never actually consents to this process — the parents consent on the infant’s behalf. Most hospitals believe this is acceptable for immediate treatment and actions, but what about future decisions that will not affect the child until he/she is old enough to consent? And if the future condition is not actionable and its potential causes more alarm than help, does anyone — parents, patient, and even the doctor — have the right to know?

Answers for these questions depend on whom you ask. The research group I followed this summer believes medicine should “do no harm.” Consequently, they believe newborn genomes should be analyzed using a panel of targeted genomic sequences — that is, a list of mutations causing conditions in newborns that are actionable and cause early onset diseases. This way, the patient will never accidently find out about mutations in their genomes that cause adult diseases. However, when the patient comes of age he or she can of course request full genome sequencing for himself/herself. Other doctors may have a more paternalistic approach because they believe as the most informed individuals in each situation, they can advocate for their patient the best. These doctors may provide the parents with all the information they find in their child’s genome. This approach, however, could possibly reveal unexpected paternity (4)  or incest (which must be reported if the mother is a minor). Whatever the preferred approach, newborn genome sequencing is proving to be one of the most promising and ethically challenging technologies in medicine (5).

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Photo by rawpixel on Unsplash

Scientists are excited about newborn genome sequencing because if a disorder is already suspected in an infant, genomic sequencing can provide more evidence for the diagnosis. Quicker and more accurate diagnoses can lead to better and more cost-effective patient care.  Questions of informed consent and data release are valid concerns about the ethics of genomic sequencing; however, some of our fears arise from a common misconception about genes believing that genes reveal everything (6). That is, if we know the patterns in our genome, we can predict our destiny. Yes, identifying the genes that may play a role in one’s obesity or depression can help doctors provide more personalized treatment therapies. But genes and bodies are very complex and cannot be treated with an entirely deterministic approach. Genetic and environmental factors alike go into each biological outcome. Genomes speak in probabilities, not predictions.

Genetic testing provides some background to our stories, but it can’t predict everything. Like most of science, it doesn’t have all the answers, but it can direct our questions. It can identify and share information that one might have not wanted to know, but also information that one may have never known otherwise. It makes us think about our responsibility as parents and caregivers. And once we are informed, it can engage us in debates that will be written into our own stories.

 

References

  1. https://kidshealth.org/en/parents/newborn-screening-tests.html
  2. https://learn.genetics.utah.edu/content/disorders/screening/
  3. https://www.cancer.gov/types/breast/risk-reducing-surgery-fact-sheet#q1
  4. https://www.theguardian.com/science/2013/sep/09/genetics-ethics-human-gene-sequencing
  5. http://www.sciencemag.org/news/2013/09/nih-studies-explore-promise-sequencing-babies-genomes
  6. https://www.theguardian.com/science/2013/sep/09/genetics-ethics-human-gene-sequencing
  7. Cover photo by João Silas on Unsplash

Hi, everyone! My name is Ege, and I am a rising second year at the University of Chicago pursuing Biological Sciences and the pre-med curriculum. When I am not killing several samples of e. coli in the lab (sorry!), I sing with my a cappella group, write for the newspaper, produce artwork, and tutor my peers. My other loves include tea, music, Ben & Jerry’s ice cream, travel, Nutella, Bones, audiobooks, the Office, and RadioLab podcasts.

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