Ata has never been an alien, but she's always been an enigma. Discovered in 2003 in a leather pouch near an abandoned mining town in Chile's Atacama Desert, the tiny, 6-inch mummy's unusual features—including a narrow, sloped head, angled eyes, missing ribs, and oddly dense bones—had both the “It's aliens!” crowd and paleopathologists intrigued. Now, a team of researchers from Stanford University School of Medicine and UC-San Francisco has completed a deep genomic analysis that reveals why Ata looks as she does.

As they lay out in a paper published this week in Genome Research, the researchers found a host of genetic mutations that doomed the fetus—some of which have never been seen before.

Stanford professor of microbiology and immunology Garry Nolan first analyzed Ata back in 2012; the mummy had been purchased by a Spanish businessman and studied by a doctor named Steven Greer, who made her a star of his UFO/ET conspiracy movie Sirius. Nolan was also given a sample of her bone marrow; his DNA analysis confirmed she was, of course, human. But Nolan's study, published in the journal Science, also found something very odd: Though she was just 6 inches long when she died—a typical size for a midterm fetus—her bones appeared to be 6 to 8 years old. This did not lead Nolan to hypothesize an alien origin for Ata, but to infer that she may have had a rare bone disorder.

The current analysis confirmed that interpretation. The researchers found 40 mutations in several genes that govern bone development; these mutations have been linked to "diseases of small stature, rib anomalies, cranial malformations, premature joint fusion, and osteochondrodysplasia (also known as skeletal dysplasia)," they write. The latter is commonly known as dwarfism. Some of these mutations are linked to conditions including Ehlers-Danlos syndrome, which affects connective tissue, and Kabuki syndrome, which causes a range of physical deformities and cognitive issues. Other mutations known to cause disease had never before been associated with bone growth or developmental disorders until being discovered in Ata.

Emery Smith

"Given the size of the specimen and the severity of the mutations … it seems likely the specimen was a pre-term birth," they write. "While we can only speculate as to the cause for multiple mutations in Ata's genome, the specimen was found in La Noria, one of the Atacama Desert's many abandoned nitrate mining towns, which suggests a possible role for prenatal nitrate exposure leading to DNA damage."

Though the researchers haven't identified the exact age of Ata's remains, they're estimated to be less than 500 years old (and potentially as young as 40 years old). Genomic analysis also confirms that Ata is very much not only an Earthling, but a local; her DNA is a nearest match to three individuals from the Chilote people of Chile.

In a press statement, study co-lead Atul Butte, director of the Institute for Computational Health Sciences at UC-San Francisco, stressed the potential applications of the study to genetic disorders. "For me, what really came of this study was the idea that we shouldn't stop investigating when we find one gene that might explain a symptom. It could be multiple things going wrong, and it's worth getting a full explanation, especially as we head closer and closer to gene therapy," Butte said. "We could presumably one day fix some of these disorders."