# Ancient DNA shows trisomy 13 in a 1,600-year-old Nasca infant with cyclopia from Jauranga, Peru

- Published: 2026-11-13 11:27 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: cyclopia ancient DNA, trisomy 13 Nasca infant, Patau syndrome archaeology, Jauranga Peru burial, holoprosencephaly, Middle Nasca period, ceramic urn infant burial
- URL: https://realtech.media/news/rt-3df8cb7692b9e2e74d69493c_ancient_dna_shows/

**Researchers sequenced DNA from an infant with a single eye socket buried in a ceramic urn in southern Peru and found three copies of chromosome 13.**

![Ancient DNA shows trisomy 13 in a 1,600-year-old Nasca infant with cyclopia from Jauranga, Peru](https://realtech.media/media/2026/11/0b2f464b45e60dd6.jpg)
*ZME Science*

Researchers examined two infants buried together in a Middle Nasca-period cemetery in Jauranga, southern Peru, dated to 325–440 CE. The study was published in the journal Proceedings of the National Academy of Sciences [1]. One infant, designated JA13A, had a single median orbit and other skeletal features diagnostic of cyclopia. The second, JA13B, showed no comparable congenital variations [1].

## Trisomy 13 in ancient DNA

DNA recovered from a leg bone of JA13A revealed an extra copy of chromosome 13. The authors identify trisomy 13, also known as Patau syndrome, as the likely cause of the malformation [1]. Three separate analytical methods supported the finding. Trisomy 13 is a major chromosomal cause of severe holoprosencephaly, although only a minority of affected babies develop cyclopia.

Cyclopia occurs in about one in 100,000 births and is almost always fatal. It arises when the developing brain fails to divide into hemispheres, which also disrupts the formation of the eyes and nose. Lead author Elsa Tomasto-Cagigao said the cause was present at fertilization.

The skeletal age indicators disagreed. The teeth resembled those of a two- to four-month-old infant, while the long bones matched a fetus of 36 to 40 weeks. Co-author Lars Fehren-Schmitz said the researchers cannot say how long the individual survived. The authors consider two explanations: survival for weeks or months with restricted skeletal growth, or disrupted tooth development that made the infant look older.

## Burial in a ceramic vessel

Both infants lay in one ceramic vessel, apparently placed during a single burial event [1]. The two were maternally unrelated, and the DNA does not show whether they shared a father. Urn burials were common for Nasca children and account for about a quarter of documented graves in Palpa. This burial contained no unusual grave goods and no obvious sign of different treatment for the infant with cyclopia.

Whether the infant received special care in life is unknown. A 2024 analysis of nearly 10,000 ancient genomes had found Down and Edwards syndromes but no Patau syndrome. This case combines skeletal, genomic and archaeological evidence for a severe congenital condition and its mortuary treatment in a past society [1].

## Sources

1. [Proceedings of the National Academy of Sciences](https://doi.org/10.1073/pnas.2625042123)
2. [ZME Science](https://www.zmescience.com/science/archaeology/a-1600-year-old-baby-had-a-single-eye-socket-ancient-dna-finally-revealed-why)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-3df8cb7692b9e2e74d69493c_ancient_dna_shows/