Breathe deep and look at the horizon. It’s the sagely advice many of us have heard who experience motion sickness, more often than not, providing little comfort. While one in three individuals is highly susceptible to motion sickness, the etiology of this disorder is not well understood. Moreover, despite its high heritability rate, the underlying genetic factors for motion sickness have yet to be uncovered.
In an effort to shed light onto the genetics of motion sickness, scientists at 23andMe have published results from what they say is the first genome-wide analysis and association study of the disorder.
“Until now there's been a poor understanding of the genetics of motion sickness, despite it being a fairly common condition,” said Bethann Hromatka, Ph.D., health content manager at 23andM and lead author of the study. “With the help of 23andMe customers we've been able to uncover some of the underlying genetics of this condition. These findings could help provide clues about the causes of motion sickness and other related conditions, and how to treat them, which is very exciting.”
The results from this genome-wide analysis study were published online in Human Molecular Genetics in an article entitled “Genetic variants associated with motion sickness point to roles for inner ear development, neurological processes, and glucose homeostasis”.
More than 80,000 samples from participants, who were consenting 23andMe customers, were analyzed and scientists found 35 genetic factors with a high correlation to motion sickness. A significant number of the genetic elements observed contained single-nucleotide polymorphisms (SNPs), either within or near genes that play a role in ocular signaling, the vestibular system of the inner ear, or cranial development (e.g., HOXB3, HOXD3, TSHZ1). Interestingly, the researchers report that many of the SNPs they found are sex specific and have a stronger effect (threefold) in women.
Another intriguing discovery that the 23andMe team described was the relationship between motion sickness and the increased likelihood of individuals to experience vertigo, morning sickness, migraines, and postoperative nausea and vomiting (PONV). Furthermore, migraines and PONV were found to share underlying genetic elements with motion sickness.
“We identified four SNPs simultaneously associated with motion sickness plus PONV or migraines. These findings may provide clues into the etiology of all three conditions and may point to overlapping risk factors or treatments,” the paper concluded.