Recent socio-economic migration within the United Kingdom has influenced the geographic distribution of human DNA linked to traits such as education levels and health, according to a new study published in Nature Human Behaviour.
“We were interested in looking at the geographic distribution of human DNA. I have studied the geographic distribution of genetic ancestry differences before, but not yet the geographic distribution of the genetic predisposition to heritable traits and diseases,” said lead author Abdel Abdellaoui of the University of Amsterdam.
“UK Biobank provided a dataset that was large enough to have a look at this, so we did for more than 30 traits and diseases, including physical and mental health, personality, and educational attainment.”
Drawing on data from 488,377 people of European descent surveyed for the UK Biobank, the researchers examined about 1.2 million genetic variants to calculate the polygenic scores — an estimate of someone’s genetic predisposition for a certain characteristic — for 33 measures related to economic, health and cultural outcomes. These included but were not limited to physical and mental health, religion, addiction, personality, BMI, reproduction, height and educational attainment.
The researchers found that 21 traits showed significant regional clustering on a genetic level after controlling for ancestry. The findings suggest that regional differences in educational attainment genes are the result of more recent selective migration within the country.
“When looking at regional differences between genes for a wide range of traits, genes that are associated with educational attainment show the largest regional differences in Great Britain. These differences are increasing over time, as higher educated individuals leave the poorer regions of the country. These poorer regions show worse living circumstances than the rest of the country, which contributes to worse health outcomes in these regions,” Abdellaoui told PsyPost.
The researchers noted that people tend to migrate to improve their skills or employment prospects. In the late nineteenth and early twentieth century, for example, many people left small farms to work industrial jobs in urban centers.
“This study has scientific as well as societal implications. There are several widely used study designs that assume that genes are randomly distributed across geography, which we show is not the case. Also, we should take better care of the poorer regions of the country, since the poor living conditions there are causing these regions to have worse health outcomes and are driving talented people away, which is increasing genetic differences between poor and rich,” Abdellaoui said.
“Our research shows that people have polygenic scores that are more similar to their neighbours’ polygenic scores than to those of people who live far away. While some of this clustering could come from ancestral differences, we find some of it seems to have a more recent origin. And, when we look at how our subjects have moved during their lifetime, we can see that this clustering is increasing,” added co-author David Hugh-Jones in a news release.
There are a few caveats, however. “The genetic effects on educational attainment are difficult to quantify, because the genetic predisposition for lower education coincides with worse living conditions that also have a detrimental effect on educational outcomes. Within family studies may offer a solution for this, which is something we are currently working on,” Abdellaoui explained.
The study, “Genetic correlates of social stratification in Great Britain“, was authored by Abdel Abdellaoui, David Hugh-Jones, Loic Yengo, Kathryn E. Kemper, Michel G. Nivard, Laura Veul, Yan Holtz, Brendan P. Zietsch, Timothy M. Frayling, Naomi R. Wray, Jian Yang, Karin J. H. Verweij, and Peter M. Visscher.
