DNA mystery: the sun sneeze
Some people sneeze when they step out into bright sunlight — it is called the photic sneeze reflex. Guess what share of the population has it.
How common is the sneeze reflex in bright light?
About one in four — an inherited reflex, not a defect.
The photic sneeze reflex has been mapped in several studies; among others the marker rs10427255 has been linked to the phenomenon in GWAS contexts. It is a dominant trait — a child of a carrier often has a chance of inheriting it.
It is an association, not a diagnosis — many factors affect whether the reflex triggers in practice.
Marker: an intergenic marker linked to photic sneeze reflex in GWAS — rs10427255. Look it up, or check your own variant against your raw data file — locally in the browser, no upload.