Your season of birth may determine allergy risk: study

The season in which you were born may be linked to your risk of allergy in later life, researchers, including those of Indian-origin, suggest. Scientists have discovered specific markers on DNA that link the season of birth to risk of allergy in later life.

The season a person is born in influences a wide range of things - from risk of allergic disease, to height and lifespan. Yet little was known about how a one-time exposure like the season of birth has such lasting effects.

Researchers including Veeresh K Patil from University of Southampton in the UK and Akhilesh Kaushal from University of Memphis in the US conducted epigenetic scanning on DNA samples from a group of people born on the Isle of Wight.

They found that particular epigenetic marks (specifically, DNA methylation) were associated with season of birth and still present 18 years later.

Researchers were also able to link these birth season epigenetic marks to allergic disease, for example people born in autumn had an increased risk of eczema compared to those born in spring. The results were validated in a cohort of Dutch children.

“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. However, until now, we did not know how the effects can be so long lasting,” said John Holloway from University of Southampton.

“Epigenetic marks are attached onto DNA, and can influence gene expression (the process by which specific genes are activated to produce a required protein) for years, maybe even into the next generation,” said Holloway.

“Our study has linked specific epigenetic marks with season of birth and risk of allergy. However, while these results have clinical implications in mediating against allergy risk, we are not advising altering pregnancy timing,” he added.

“It might sound like a horoscope by the seasons, but now we have scientific evidence for how that horoscope could work,” said Gabrielle Lockett from University of Southampton.

“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,” Lockett said. The findings were published in the journal Allergy.