New (half-)Ashkenazi Sample from Medieval Sweden
A newly released preprint, "Genomic impact of the second plague pandemic on three human populations," included a surprising find: a half-Ashkenazi child who lived in Sweden between the 14th and 16th centuries.
The child was buried in a mass grave among people of nordic background centuries prior to any known Jewish presence in Scandinavia. The child's paternal haplogroup was E-PF1975, a charactaristically Jewish lineage, while the maternal haplogroup was H27h1a, a European haplogroup which is not known to be present among Jews.
The sample also has quite high IBD sharing with modern Ashkenazim yet had very low homozygosity, suggesting the child had an Ashkenazi father who migrated to Sweden, assimilated into the local culture, and married a woman of northwestern European background.