A 15-year-old girl from the U.K. is suffering from a rare condition that causes her brain to shrink, London's Daily Mail reported.

Paige Badman has Pitt Hopkins syndrome — a condition so rare that it only affects 12 people in the world — and it could take her life at any moment.

Paige was diagnosed with the condition four years ago, but there isn't much treatment available. The disease causes her to have difficulty breathing, and she is unable to eat or speak. She also suffers frome epilepsy. Doctors have told Paige's parents that their daughter's brain is like that of a 70-year-old.

Paige's parents have celebrated Christmas every day since the beginning of November, in case Paige doesn't survive until Dec. 25.

Rachel Badman, Paige's mother, described her daughter's illness "like being on death row."

"Doctors say she will just fall asleep one day and not wake up, and I almost hope it might happen soon just end the suffering," Badman said.

Click here to read more on this story from the Daily Mail and to see pictures of Paige.