Tracking Multiple Sclerosis Origins
Ancient DNA Illuminates Genetic Insights
A groundbreaking study1 reveals how migratory patterns from Asia to Europe 5,000 years ago brought not only pastoral life but also genetic risk factors for multiple sclerosis (MS). Shedding light on the enigmatic prevalence of MS in Northern Europeans, the research suggests an evolutionary trade-off and underscores the intricate interplay between genetics, environment, and disease.
Multiple sclerosis, or MS, is an autoimmune condition affecting 1 in 1,000 individuals and most prevalent in Northern Europe. MS finds its origins intertwined with human migration and adaptation. The study's findings, published in Nature, offer a compelling narrative of genetic evolution, spotlighting the selective advantage of immune-related genes amid ancient environmental challenges.
The research team meticulously examined DNA samples from over 300 ancient individuals, spanning 25,700 to 1,200 years ago. By deciphering ancient genomes, they uncovered a rich tapestry of human ancestry and migration waves across Eurasia, illuminating the foundations of modern-day European populations. Drawing on DNA analysis of ancient human bones and teeth, the study traces a pivotal migration event 5,000 years ago when pastoralist herders, the Yamnaya people, introduced genetic variants to Western Europe. While advantageous in ancient environments, these genetic variants now heighten MS risk in modern populations.
One of the study's notable revelations concerns MS, revealing a genetic legacy shaped by millennia-old encounters with pathogens. While the precise mechanisms remain under scrutiny, the findings suggest that ancestral immune responses to infectious threats inadvertently laid the groundwork for the autoimmune dysregulation seen in MS today.
Co-author Professor Lars Fugger underscores the significance of these findings in reshaping our understanding of MS. He emphasizes the transition from conventional perceptions of MS as solely disease-driven to recognizing its genetic underpinnings rooted in ancient adaptations. As over 200 MS-genetic risk variants are mapped, the study sheds light on their historical role in protecting against ancient infectious diseases.
Professor Astrid Iversen further explores the ongoing evolutionary dynamics of the human immune system in response to pathogen challenges. Investigating the impact of environmental and lifestyle factors since the Last Ice Age, her research elucidates present-day genetic susceptibility to diseases like MS. The findings highlight the continuous evolution of the immune system and its implications for modern disease susceptibility.
Looking ahead, the research team aims to extend their investigations to other neurological and psychiatric disorders. By harnessing ancient DNA and contemporary genetic data, they seek to unravel the intricate genetic landscape underlying various diseases, paving the way for targeted therapies and enhanced disease management strategies.
The study underscores the profound implications of this ancestral genetic legacy in understanding and treating complex diseases like MS. While the journey from genetic discovery to clinical application is multifaceted, the study paves the way for a deeper comprehension of human biology and disease susceptibility.
As we unravel the mysteries encoded in ancient DNA, we gain invaluable insights into our past, present, and future. The quest to decipher the genetic roots of human illness holds promise for novel therapeutic interventions and a deeper appreciation of our evolutionary heritage.
Barrie, W., Yang, Y., Irving-Pease, E. K., Attfield, K. E., Scorrano, G., Jensen, L. T., Armen, A. P., Dimopoulos, E. A., Stern, A., Refoyo-Martinez, A., Pearson, A., Ramsøe, A., Gaunitz, C., Demeter, F., Jørkov, M. L. S., Møller, S. B., Springborg, B., Klassen, L., Hyldgård, I. M., … Willerslev, E. (2024). Elevated genetic risk for multiple sclerosis emerged in steppe pastoralist populations. Nature, 625(7994), 321–328. https://doi.org/10.1038/s41586-023-06618-z