The discovery in 2003 sparked international intrigue -- a tiny, mummified skeleton with an alien-like head, tucked into a leather pouch found behind a church in the Atacama desert of Chile.
The notion that it was an extra-terrestrial was long ago debunked, but researchers said Thursday they have gleaned new insights from a full genetic analysis which showed the skeleton, nicknamed "Ata," belonged to an infant girl with a handful of rare gene mutations linked to dwarfism, deformities and apparent premature aging.
Experts have said previously the bones appeared to belong to someone between the ages of six and eight, said the study in Genome Research.
"We now know that it's a child, and probably either a pre- or post-term birth and death," said senior author Garry Nolan, professor of microbiology and immunology at the Stanford University School of Medicine.
The skeleton's intact condition suggests it is probably no more than 40 years old.
The child had a never-before seen rib count of 10 pairs. Humans typically have 12 pairs.
Using DNA extracted from the bone marrow, researchers did a whole-genome analysis which determined that she was South American, "with genetic variations that identified her as being from the Andean region inhabited by the Chilean Chilote Indians," said the report.
Nolas said "a relatively short list of mutations in genes known previously to be associated with bone development" were found in genes related to dwarfism, scoliosis, and musculoskeletal abnormalities.
Some were previously known to scientists, others were not.
The discovery could one day lead to treatments for people with bone problems, said Nolan.
"Maybe there's a way to accelerate bone growth in people who need it, people who have bad breaks," he said.
"Nothing like this had been seen before. Certainly, nobody had looked into the genetics of it."
For now, though, he urged the skeleton -- which is owned by a Spanish archeological collector -- to be returned to Chile.
"I think it should be returned to the country of origin and buried according to the customs of the local people."