Hi everyone! I know right now is a tense and anxious time, so I wanted to just have some fun and remind myself and others why we signed up for genetic counseling in the first place. We want to help people experiencing genetic conditions, for sure! And we also just find genes cool. I’ve sometimes been surprised at the weird and wonderful genes that humans have. Here’s a few cool genes found in the human genome, and what they do.
ADAR1 protects the human body from both viruses and autoimmune disorders. It encodes an enzyme which plays an important role orchestrating immune responses. When this enzyme senses the presence of a few stray viral strands, it actually escorts those strands further into the body, shielding them from the immune system.
Why? This enzyme protects us from an overstimulated and overactive immune system. If we can withstand a small viral threat without a systemic immune response, it is better for us to do that than to trigger the immune system. When the immune system responds, we start to feel ill. ADAR1 will activate this response only if it recognizes a formidable threat. The enzyme encoded by ADAR1 maintains a delicate balance of appropriate reactions to viral threats, keeping us feeling our best.
ADAR1 wiki: https://en.m.wikipedia.org/wiki/ADAR
ACHOO Syndrome (caused by a mutation on Chromosome 2)
Most genetics nerds know this one— the photic sneeze reflex! It’s a dominantly inherited condition causing affected individuals to sneeze when suddenly exposed to bright light. It’s most common in white females, and yes, that includes me! It’s one of my favorite genetic quirks. Whenever it happens to me, I bring up its fascinating folklore.
It’s thought that photic sneezing may have developed during early hominid history, when our ancestors lived in dark, musty caves. These caves may have exposed them to high concentrations of mold, bacteria, and other particulates. It’s hypothesized that this random mutation became beneficial to early man, as sneezing upon exiting their caves prevented them from becoming ill from cave particulates. Thus, the mutation persisted in future generations as it aided in early hominid survival. And now? I just get to sneeze every time I leave a movie theatre.
MC1R is the redhead gene. Mutations in this gene cause, no surprise, red hair! The gene produces pheomelanins, the pigments that give the lips, nipples, and groin their pinkish color. When those pheomelanins are found in hair, and not overpowered with dark-hair melanins, the hair will be red.
And how I wish I had some of those pheomelanins in my hair, it would save me a lot of effort with red hair dyes. 😅👩🏻🦰
These same mutations are actually associated with many other traits, leading to the historical stereotyping of natural redheads. Redheads process pain differently and require more analgesics for medical procedures. Their lack of darker melanins leads to exceptionally fair skin, which burns quite easily. These associated traits contribute to stereotypes that redheads are feisty because they process pain differently, or nerdy because they can’t get sun very well!
Oh, and red hair isn’t going to die out. MC1R is recessive so it will continue to pass from generation to generation, even if it’s carriers don’t themselves have red hair.
Redhead wiki: https://en.m.wikipedia.org/wiki/Red_hair
FGF21 is the 21st gene in a long line of fibroblast growth factors. Sounds like a snoozer. But cool fact, mutations in it are associated with having a sweet tooth!
FGF21 in its wild-type or “normal” state protects us from obesity, fatty liver, and high blood sugar. Mutations can make us sensitive to these conditions, and prone to eat the foods that contribute to them. Yikes. Genetic researchers are currently studying this gene as a potential genetic contributor to Type 2 Diabetes, with the hope of unlocking some therapies to treat it.
For now, if you’re plagued with a sweet tooth like me, take extra care to watch out for your health! I’m right there with you trying to fight the urge to eat an entire gallon of ice cream in one sitting
FGF21 wiki: https://en.m.wikipedia.org/wiki/FGF21
And there you have it, a few interesting genes to ponder today! I know we’re all stuck inside, some of us awaiting grad school results, and all of us wishing for something to think about other than the walls of our house. We’ll get through this together. Stay safe and happy!