Down syndrome identified in 2600-year-old infants through their DNA

Between 770 and 550 B.C.E., in a hilltop village called Alto de la Cruz near the modern Spanish city of Navarro, one infant girl received an unusual burial: Although people in Iron Age Spain usually cremated their dead, the girl was laid to rest beneath the floors of an elaborately decorated dwelling, with grave goods including bronze rings, a shell from the Mediterranean, and three whole sheep or goats. And she wasn’t alone: Archaeologists working in the 1940s and ’50s found dozens of infants buried below the floors in Alto de la Cruz and another nearby village built more than 2600 years ago. “The main question was: What is special about these children?” says Roberto Risch, an archaeologist at the Autonomous University of Barcelona. Now, researchers know that four of the 35 buried babies had chromosomal abnormalities and likely could not have lived long, given the medical care of the time. In a study published today in Nature Communications , researchers discovered that the girl with rings and two other buried infants had Down syndrome, also known as trisomy 21. Another infant had trisomy 18, or Edwards syndrome. It’s the first time the latter condition has been identified in the archaeological record. “This was totally unexpected,” says Risch, a co-author of the new study. Given that Down syndrome occurs in an estimated one in 700 pregnancies today, “four out of 35 is quite a lot.” The study supports previou...
Source: ScienceNOW - Category: Science Source Type: news