It has long been acknowledged that the season during which you were born can influence you throughout your life in many ways – your height, lifespan, and maybe even your temperament. In fact, research has found a strong connection between the season of someone’s birth and their personality. A study in European College of Neuropsychopharmacology found that people born in the summer are more likely to experience mood swings, those born in autumn are less likely to be depressive, and those born in winter are less likely to be irritable. Other studies suggest that someone’s month of birth might be linked to suicide risk or determine whether or not they develop food allergies. Now, new evidence focusing on epigenetics and allergies could hold the key to understanding this mysterious phenomenon. A recent epigenome-wide association study (EWAS) published in Allergy, reveals a unique DNA methylation profile related to birth season and connects this with one’s risk of developing allergies. This epigenetic revelation could even be the missing piece to the mechanism underlying many other seasonally influenced diseases and traits.
The study, conducted by scientists at the University of Southampton, uncovered a connection between season of birth and epigenetic marks, specifically DNA methylation. The team of researchers assessed DNA samples of people born on the Isle of Wight and found that, not only were their DNA methylation marks linked to their season of birth, but these epigenetic marks were present for several years after they were born. Taking this a step further, these unique birth season DNA methylation marks were related to allergic disease. For instance, individuals who were born in the fall, compared to those born in the spring, actually had an increased risk of eczema, a chronic skin condition that puts people at risk of developing food allergies, asthma, and hay fever. They used a cohort of Dutch children to validate their results.
One of the study’s authors and Professor of Allergy and Respiratory Genetics at the University, John Holloway, said, “These are really interesting results. We know that season of birth has an effect on people throughout their lives. For example generally, people born in autumn and winter are at increased risk for allergic diseases such as asthma.”
What they didn’t know, however, was how long-lasting the effects could be. DNA methylation, perhaps the most widely studied epigenetic mechanism, is known to impact gene expression by adding a methyl group onto DNA. Typically, greater methylation leads to a gene turning off and the reduction or absence of its corresponding protein. Holloway and his team found that the methylation marks related to season of birth actually persisted for 18 years.
Although Holloway indicated that they have “linked specific epigenetic marks with season of birth and risk of allergy [and] these results have clinical implications in mediating against allergy risk,” they aren’t advising people to change the time at which they want to get pregnant.
The first author of the study who is also from the University of Southampton, Dr. Gabrielle Lockett, commented: “It might sound like a horoscope by the seasons, but now we have scientific evidence for how that horoscope could work. Because season of birth influences so many things, the epigenetic marks discovered in this study could also potentially be the mechanism for other seasonally influenced diseases and traits too, not just allergy.”
So, could DNA methylation and the season of your birth be to blame for your allergies? The authors press for further research in order to gain a comprehensive understanding of how different seasons might epigenetically impact disease risk and whether temperature, sunlight, and diet might play a role as well. Additional evidence is also needed to substantiate the connection between DNA methylation and allergies and whether exposure to environmental factors could impact the epigenome and an individual’s likelihood of developing certain diseases. Although other mechanisms are likely to be involved, this study on epigenetics and DNA methylation is an interesting piece to the puzzle of seasonally influenced diseases and traits.
Source: Lockett, G.A., Soto-Ramírez, N., Ray, M.A., Everson, T.M., Xu, C., Patil, V.K.. Terry, W., Kaushal, A., Rezwan, F., Ewart, S.L., Gehring, U., Postma, D.S., Koppelman, G.H., Arshad, S.H., Zhang, H., Karmaus, W., Holloway, J.W. (2016). Association of Season of Birth with DNA Methylation and Allergic Disease. Allergy.
Reference: University of Southampton. DNA markers link season of birth and allergy risk. University of Southampton News and Events. 21 Mar 2016. Web.
