PT  - JOURNAL ARTICLE
AU  - Shamam Waldman
AU  - Daniel Backenroth
AU  - Éadaoin Harney
AU  - Stefan Flohr
AU  - Nadia C. Neff
AU  - Gina M. Buckley
AU  - Hila Fridman
AU  - Ali Akbari
AU  - Nadin Rohland
AU  - Swapan Mallick
AU  - Jorge Cano Nistal
AU  - Jin Yu
AU  - Nir Barzilai
AU  - Inga Peter
AU  - Gil Atzmon
AU  - Harry Ostrer
AU  - Todd Lencz
AU  - Yosef E. Maruvka
AU  - Maike Lämmerhirt
AU  - Leonard V. Rutgers
AU  - Virginie Renson
AU  - Keith M. Prufer
AU  - Stephan Schiffels
AU  - Harald Ringbauer
AU  - Karin Sczech
AU  - Shai Carmi
AU  - David Reich
TI  - Genome-wide data from medieval German Jews show that the Ashkenazi founder event pre-dated the 14<sup>th</sup> century
AID  - 10.1101/2022.05.13.491805
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.05.13.491805
4099  - http://biorxiv.org/content/early/2022/05/16/2022.05.13.491805.short
4100  - http://biorxiv.org/content/early/2022/05/16/2022.05.13.491805.full
AB  - We report genome-wide data for 33 Ashkenazi Jews (AJ), dated to the 14th century, following a salvage excavation at the medieval Jewish cemetery of Erfurt, Germany. The Erfurt individuals are genetically similar to modern AJ and have substantial Southern European ancestry, but they show more variability in Eastern European-related ancestry than modern AJ. A third of the Erfurt individuals carried the same nearly-AJ-specific mitochondrial haplogroup and eight carried pathogenic variants known to affect AJ today. These observations, together with high levels of runs of homozygosity, suggest that the Erfurt community had already experienced the major reduction in size that affected modern AJ. However, the Erfurt bottleneck was more severe, implying substructure in medieval AJ. Together, our results suggest that the AJ founder event and the acquisition of the main sources of ancestry pre-dated the 14th century and highlight late medieval genetic heterogeneity no longer present in modern AJ.Competing Interest StatementShai Carmi is a paid consultant and holds stock options at MyHeritage. Daniel Backenroth is an employee and shareholder at The Janssen Pharmaceutical Companies of Johnson & Johnson. Eadaoin Harney is an employee of 23andMe.