What do nearsightedness, stretch marks, and motion sickness have to do with each other? They don’t appear to be genetically related – at least not according to our in-house statistical geneticists – but all of them are relatively common and annoying. These three conditions are also making 23andMe scientists happy since all of them are hot on the research wagon!
Scientists at 23andMe are gearing up for the annual American Society of Human Genetics
(ASHG) meeting and will be presenting on all of these topics. Here are some highlights:
Are My Genes Making me Myopic?
Myopia, or nearsightedness, is thought to be highly heritable – if your mother wore glasses to see the chalkboard chances are you might need them – but until now scientists have only known a little about the underlying genetics.
23andMe scientist Amy Kiefer* will present results from a genetic study carried out with data from 23,000 nearsighted customers and 16,000 controls, all with European ancestry. The analysis identified associations between 17 genetic factors and myopia and replicated the only two previously identified associations in Europeans. Many of the new factors are located in genes that play important roles in eye development and function. This analysis is the largest ever gene association study on this topic.
Making a Stretch for My Genes
Some of us are all too familiar with stretch marks – red or white lines that appear on the skin, often after pregnancy. The appearance of these marks has encouraged many to open their wallets (to the tune of $5-10 billion annually) and fill their cupboards with cosmetics that claim to prevent or treat stretch marks.
But despite the range of products promising to “make those lines vanish”, very little is understood about what causes them in the first place. And up until 23andMe took a stab, no genetic factors had been associated with stretch marks in the general population.
Meghan Mullins* from 23andMe will present results from a genetic study with 30,000 customers who responded to the following question on the 23andMe website: “Do you have stretch marks on your hips, thighs, or backs of your arms? Yes/No/I’m not sure”. The analysis identified an association between stretch marks and a variant near a gene called elastin. Defects in the elastin gene are known to affect the integrity of the skin as well as cause heart defects. This study also identified an association between stretch marks and a variant in a protein called SRPX, but more work is needed to understand how this protein could play a role in this condition.
A Motion for the Genetics of Motion Sickness
Roughly one in three individuals is highly susceptible to motion sickness; the remaining two-thirds of the population may experience motion sickness if the conditions are extreme. We understand what provokes motion sickness – traveling in cars, boats, planes, and also more unusual modes of transportation like skiing or riding a camel. Partaking in simulator experiments, for instance those carried out by the US Air Force and NASA, and escaping into virtual reality environments (aka playing video games) can also provoke motion sickness.
It’s estimated that up to 70% of a person’s risk for motion sickness is due to genetics, but the genetics of motion sickness has been very poorly understood … until now.
23andMe scientist Bethann Hromatka* will present results from a genetic study of nearly 37,000 customers who were surveyed about motion sickness. The analysis identified 14 genetic associations with motion sickness that fall into a few different biological categories. Three genetic variants are involved in development, including development of the eye and ear. Other variants are involved neurological processes and glucose/insulin regulation.
*Numerous 23andMe employees contributed to these studies. Statistical geneticist Nicholas Eriksson carried out the genetic analyses and others on the 23andMe Research Team contributed to survey design, data analysis, and scientific review.