The Sun Sneeze Gene

TL;DR

Some people sneeze when they are exposed to bright sunlight, known as the photic sneeze reflex, and scientists have discovered a gene mutation responsible for this phenomenon.

Transcript

I am a sun sneezer. Which is also known as having the photic sneeze reflex Or, the autosomal dominant compelling helio ophthalmic outbursts syndrome. Which basically means if I go from a dark area into somewhere that's brightly lit - You know, like, looking at the sun - I will sneeze. Wait for it... There you go, I'm a sun sneezer. But why does th... Read More

Key Insights

• ❓ The cause of the photic sneeze reflex is still not fully understood, with different theories proposed.
• 🔅 Sneezing in bright sunlight may have an evolutionary advantage by reducing the spread of diseases.
• 👯 Approximately one in four people exhibit the photic sneeze reflex, suggesting it is a relatively common trait.
• 💌 The gene responsible for the reflex is located on the second chromosome and involves a single-letter change in the DNA sequence.
• 😎 The trigeminal nerve, responsible for facial sensations, is believed to play a role in the occurrence of sun sneezing.
• 🧑‍🚒 The photic sneeze reflex is generally harmless, but it may be problematic in certain situations like flying a fighter jet or performing delicate surgeries.
• ❓ 23andMe, a company specializing in DNA analysis, has identified the gene polymorphism associated with the photic sneeze reflex.

Questions & Answers

Q: Why do people sneeze when they go from a dark area into bright sunlight?

The exact cause is uncertain, but it is believed that the stimulation of the optic nerve may cross over into the maxillary branch, causing a tickle and subsequently a sneeze.

Q: Does everyone have the photic sneeze reflex?

No, only about 18 to 35 percent of people exhibit this reflex.

Q: Is the photic sneeze reflex hereditary?

Yes, studies have shown that the trait is autosomal dominant, meaning that inheriting a single copy of the gene from one parent is enough to exhibit the reflex.

Q: Can the gene responsible for the photic sneeze reflex be identified through DNA analysis?

Yes, a study conducted in 2010 analyzed the DNA of individuals who reported being sun sneezers, and they found a specific gene polymorphism associated with this trait.

Summary & Key Takeaways

• The photic sneeze reflex has been known for thousands of years, with different theories explaining the cause.

• Sneezing in bright sunlight may have an evolutionary advantage by reducing the spread of pathogens.

• The photic sneeze reflex is hereditary, with only 18 to 35 percent of people having this trait.