Discovery 5 of 10

Sneezing in the sun

Have you ever sneezed after leaving the house on an exceptionally sunny day? It turns out that sneezing "in the sun" even has a name, and of course there is a genetic basis for it. Autosomal-Dominant Compelling Helio-Opthalmic Outburst, or in short: ACHOO.

Though it may sound funny, it isn’t a joke. Scientists at Stanford University have led research on this topic and showed that it's a matter of single nucleotide replacement in our DNA, just one cytosine instead of thymine, which makes us sneeze when exposed to intense sun. Although the exact mechanism of this phenomenon is not yet known, it is already known that it involves irritation of the trigeminal nerve - one of the cranial nerves.

Coming back to our Polish population analyzed in the project, all this indicates that we sneeze in the sun less often than others. Our chances for the so-called photic sneeze effects are slightly lower than among other Europeans. The MAF (minor allele frequency) for the variant, referred to in the literature as rs11856995, correlated with the less frequent incidence of "sun sneezing", is 23% for the general population (GnomAD v3.1.1), but in the Polish population it is estimated at 36%.

The Thousand PolishGenomes Project - a national database of Polish variant allele frequencies" is a unique scientific project, the aim of which was to create the first database of genetic variants of Poles and Polish women. The presented results come from this project.

Find out more about sneezing in the sun:

P.S. Of course, there exists data that is less extensive than WGS analyzes from other populations, but with a much larger sample size, for example in 23andMe or FTDNA collections. In this project, however, we focused only on data from genome-wide projects. Remember that the The Thousand PolishGenomes project is open to more discoveries by other research groups in the upcoming groups, and the presented results are only the tip of the iceberg. 

P.S. Picture from