The Faroe Islands. Image credit: Hamid et al. (CC BY-SA 4.0)
Our DNA contains a wealth of information about our ancestors. By examining the DNA of present-day populations, researchers can infer aspects of their history, including migration patterns, interactions with other groups, changes in population size, and adaptation to local environments.
When a small group of “founders” settles a new location, they carry only a subset of the larger population’s genetic diversity. As a result, their descendants often exhibit reduced genetic diversity and elevated frequencies of certain genetic variants, some of which may influence health, disease, or adaptation.
The Faroe Islands, a remote North Atlantic archipelago, were settled around the 9th century CE, primarily by people from Scandinavia and the British Isles. Today’s population of approximately 54,000 Faroese descends from this relatively small founding group. This distinctive demographic history – characterized by mixed ancestry, geographic isolation, and a limited number of founders – is likely reflected in the genomes of present-day Faroese individuals.
To investigate the genetic diversity, ancestry, and evolutionary history of the Faroese population, Hamid et al. conducted whole-genome sequencing on 40 individuals selected to represent the geographic diversity of the islands. Previous studies of the Faroese population were limited either to small sample sizes (fewer than 10 individuals) or to specific regions of the genome, leaving substantial gaps in our understanding of the population’s full genetic landscape. The Faroe Islands also have elevated rates of several diseases, including inflammatory bowel disease and type 2 diabetes, compared with other European populations. Understanding the unique genetic architecture and demographic history of the Faroese population may therefore provide important insight into the genetic basis of these health disparities.
The analyses revealed that Faroese individuals carry numerous rare and potentially disease-associated genetic variants that are absent from mainland European populations, including variants predicted to disrupt gene function. Compared with other European groups –including Finns, another well-known founder population – Faroese genomes contain longer runs of homozygosity (long, identical DNA segments), reflecting extensive segments of identical DNA inherited from common ancestors. This pattern suggests a stronger or more recent population bottleneck in the Faroese population.
Hamid et al. also identified signatures of natural selection in genes involved in vitamin D metabolism and dietary fat absorption (SLC10A1), as well as DNA repair (POLQ), which may reflect adaptation to the Faroese environment and traditional diet. Comparisons with ancient European genomes indicated that the Faroese derive approximately equal ancestry from Iron Age “West European” (Celtic-related) and “North European” (Viking-related) populations. Importantly, the data suggest that this genetic mixing likely occurred before the settlement of the islands rather than afterwards.
These findings have direct relevance for the Faroese population because they identify genetic variants enriched in the islands that may contribute to conditions such as glycogen storage disease, ankylosing spondylitis, and other disorders. In the future, this knowledge could help inform disease prevention strategies and clinical care in the Faroe Islands. However, the study of Hamid et al. represents only a pilot phase. A greater ongoing effort, the FarGen project, aims to integrate genomic data with detailed health records to better understand the relationship between genetics and disease in the Faroese population. More broadly, the Faroe Islands provide an important model for studying how historical isolation and founder effects shape genetic diversity and disease risk in human populations worldwide.
