EP19.008 Explaining close relatedness and the founding of the Faroe Islands from a bottleneck effect observed in ROHs: Abstracts from the 57th European Society of Human Genetics (ESHG) Conference: e-Posters. Eur J Hum Genet 32 (Suppl 2), 904–1230 (2024). https://doi.org/10.1038/s41431-024-01733-5

Background/Objectives: The population of the Faroe Islands, about 50,000 people, is an isolated community with a high incidence of rare diseases, e.g., Primary Carnitine Deficiency (1:300). For diagnostic purposes, some cases not affected by known mutations were whole-genome sequenced at high coverage (x37). Here, the genomes from consenting individuals are utilized to explore the genomic variation and the ancestral history of the population.
   Methods: We determine the number of SNPs and heterozygosity for eight individual and merged samples. We study the pairwise relatedness through kinship, inbreeding from runs of homozygosity (ROHs), and analyse the minor allele frequency distribution. Additionally, the population ancestry and the timing of the founding event are estimated.
   Results: Close relatedness was found between all the supposedly unrelated individuals. From ROHs, the high relatedness is interpreted as an ancient property of the isolated population. A bottleneck effect is estimated, starting between years 50 and 300 AD, with a maximum effect in the year 600 AD. A distinct clustering near the central European and British populations of the 1000 Genome Project is likely the result of the population isolation and genetic drift. The minor allele frequency distribution suggests many rare variants.
   Conclusion: The ancestry is European, while inbreeding is higher compared to
contemporary European populations and population isolates. The Faroese population exhibits inbreeding like ancient Europeans. We discovered a bottlenecked and consanguineous population event starting in the 1st-4th century, potentially 2-3 centuries earlier than previously believed based on archaeological findings.