A New York Times article has just reported a new “mutant superpower.” In Iceland, a brand new genetic trait was discovered, in which 2% of the population can’t smell the stinky odor of fish.
A study of 11,326 Icelanders was conducted, in which each participant was given six “Sniffin’ Sticks (pens imbued with synthetic odors)” of cinnamon, peppermint, banana, licorice, lemon, and fish. The participants were then asked to identify the odors based on how strong each smell was and how good each Sniffin’ Stick smelled. Across the majority, the fish was rated the lowest in pleasantness. However, a small group of people actually enjoyed the scent, noting that it smelled like caramel or even a rose.
This small group of participants was discovered to have a genetic mutation that enables the TAAR5 gene to form. TAAR5 (Trace Amine Associated Receptor 5) aids in making proteins that recognize trimethylamine (TMA), a chemical found in rotten and fermented fish, and some bodily fluids, including sweat and urine. TAAR5 is also a G Protein, meaning that it binds guanine nucleotides. And, like other coding proteins, TAAR5 is a quaternary structured protein that has three subunits. Because this protein is incapable of binding guanine nucleotides, it means that there will be at least one “broken” copy of the gene that codes for the inability to smell fish.
To simplify: TAAR5 recognizes the chemical of smell in fish (TMA), however, with the mutation that prevents the TAAR5 from forming, the smell of fish (TMA) is unrecognizable.
Interestingly, research has shown that this mutation may be a reaction to the customs of Iceland and a possible next step in the evolution of the region. In Iceland, fish takes a prominent place on most menus including dishes like “rotten shark.” These cultural and possibly smelly dishes may explain why this mutation is much more prominent in Iceland compared to Sweden, Southern Europe, and Africa (where the study was repeated). Bettina Malnic, an olfaction expert at the University of Sao Paulo in Brazil, commented on the luck of the region study took place, saying, “if they hadn’t looked at this population, they might not have found the variant [of TAAR5].”
I am VERY sensitive to smell and, at the same time, a lover of sushi, so it definitely fascinates me that there are people out there who don’t have to deal with the odor of smelly fish. This mutation is definitely one I wish I obtained. What do you think about this? Do you think you could have this mutation?!