A 20-year-old woman who has not aged in the past 15 years appeared again recently on television, as doctors and researchers remain mystified about her condition. It appears there is no one else in the world who has the same condition as Brooke Greenberg.

Brooke Greenberg Medical Mystery: 20-Year-Old Toddler, Only Case in the World? (Image: KatieCouric.com)

Brooke Greenberg, born on Jan. 8, 1993, remains a toddler in physical appearance. The ABC talk show 20/20 featured Brooke in June 2006. The young girl has been seen worldwide, but answers surrounding her condition remain shrouded in mystery. Even her DNA won't give easy clues. Why has she not aged?

Dr. Eric Schadt, who recently appeared on the syndicated talk show "Katie" (with Katie Couric) with Greenberg, wrote an explanation on Couric's website.

"For the past 15 years, by all outward appearances Brooke has not aged. She has not gone through any of the hallmark changes that would be expected to occur in a toddler as they move through their pre-teen years," he wrote.

Dr. Schadt is the director of the Icahn Institute for Genomics and Multiscale Biology at the Mount Sinai Medical Center in New York.

Researchers "have searched for genes that are mutated in ways that are specific to Brooke (compared to her parents, three normal sisters, and others in the human population who have been sequenced) and found a handful of genes that are of interest. We are in the process of assessing what these genes do in Brooke," Dr. Schadt continued.

Syndrome X: Brooke Greenberg Holds Clues to Fountain of Youth?

"If you could take a pill at any point in your life to slow or even suspend the aging process, would you do it?" asks Dr. Schadt. This implies further research into Brooke's condition could lead to the proverbial fountain of youth.

It seems there are more than one mysteries surrounding Brooke's condition. When Brooke was 4 years old, she slipped into a coma for 14 days. Doctors found a brain tumor, but by the time Brooke woke up, the tumor had disappeared. It appears Brooke's system is able to overcome medical complications by unconventional ways. Doctors have called Brooke's condition "Syndrome X." No similar case has been reported, so far.

VIDEO: Brooke Greenberg, Forever Young?

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