A collaborative team of researchers from Germany, Spain, Finland, and several other countries undertook a comprehensive genomic study of nearly 10,000 ancient individuals to identify chromosomal disorders. The research appears in Nature Communications, a prominent scientific publication (Nature Communications).
In this investigation, researchers analyzed genetic material dating from five thousand to two and a half thousand years ago. The samples were sourced from burial sites across the Iberian Peninsula in Spain, offering a window into health and heredity during late prehistoric to early historic times.
Among the 9,855 genomes that could be reliably assessed, six instances of trisomy 21, commonly known as Down syndrome, were identified, along with one instance of trisomy 18, Edwards syndrome, a rarer and typically more severe condition. In every case, the individuals carrying the chromosomal abnormalities did not survive to adulthood, dying before birth or shortly thereafter.
The findings indicate that the frequency of Down syndrome at the tail end of the Stone Age and the dawn of the Iron Age was roughly four times lower than contemporary rates. This difference is interpreted in light of the high infant mortality that characterized ancient populations, which would have reduced the likelihood that children with such conditions survived long enough to be counted in overall prevalence statistics.
Beyond the genetic data, the study provides a glimpse into social responses to disability in ancient communities. Researchers observed that children with visible or presumed genetic differences were treated as full members of their groups, receiving respect during funerary rites and maintained as part of the communal memory. These practices underscore a nuanced approach to disability that contrasts with some later historical periods and highlights the social dimensions of health in the past.
In parallel work, other scholars have shed light on the oldest known mummies in Egypt, contributing to a broader understanding of ancient health and burial practices across regions. This composite view helps historians and scientists piece together how ancient societies perceived and managed congenital conditions, as well as how these conditions intersected with family structure, community roles, and ritual life.