Megan Ham has lissencephaly, a neurological disorder that causes as many as 70 seizures a day. She can't walk or talk, and it's difficult for her to express emotion.
But Megan is a fighter and a huge fan of Bieber. When a Bieber song comes on, she smiles and kicks her feet.
"It makes me want to cry, makes me happy. When she's happy, I'm happy. When she's healthy, I'm happy. So it's a pretty big deal," said her father, Michael Ham.
When Bieber heard about Megan, he took to his Twitter account, promising to meet her when his tour hits Portland later this year.
Early on, doctors told Megan's parents she wouldn't live past 2 years old.