Thursday, April 26, 2012


Some people sneeze when they look at the sun. This trait, known as the photic sneeze reflex, or ACHOO (Autosomal-dominant Compelling Helio-Ophthalmic Outburst) syndrome, was thought to be an autosomal dominant trait. Approximately one-third of people are estimated to be sufferers of ACHOO. Recent data analyzed from the 23andMe dataset suggests the genetic influence for this trait is not simply an autosomal dominant trait. Unfortunately this may put at risk the excellent acronym for the trait. Interestingly, or merely coincidently, SNPs in proximity to two genes related to syndromes where seizures are a common symptom demonstrate statistically significant association with ACHOO. The association of the trait with seizures has been hypothesized previously.
What I find surprising is how many people are completely unaware of ACHOO considering as many as one-third of us suffer from this debilitating trait. This is perhaps best epitomized by the 23andMe questionnaire for AHCOO.
Participants were asked one question for this trait: “Do you have a tendency to sneeze when exposed to bright sunlight?” Available answers were “Yes” and “No, what are you talking about?” People who did sneeze were treated as cases, those who did not were controls.