Bieber fever isn’t a bad thing — in fact, for one seriously ill Belieber, it may be keeping her alive.

Megan Hamm, an 11-year-old girl from Vancouver, WA, has one of only 1,500 known cases of lissencephaly in the world. The disease is extremely rare and, according to the National Institute of Neural Disorders and Stroke (NINDS), its symptoms can include, “unusual facial appearance, difficulty swallowing, failure to thrive, muscle spasms, seizures, and severe psychomotor retardation. Hands, fingers, or toes may be deformed.” Children with the disease rarely live past age 10 and often never develop intelligence beyond the level of a 3-5 month old.

Hamm’s doctors reportedly told her family that in addition to never walking or talking, Megan would never recognize them or express emotion.

That prognosis is proven wrong every time Megan hears Justin Bieber’s music.

When she hears music by the Biebs, Hamm begins to kick her feet and even smiles. The reaction is so unusual and visceral that a switch was installed on her wheelchair allowing her to listen to his music whenever she wants. It’s a reaction doctors thought was impossible.

And it seems the Biebs has seen Hamm’s amazing story. This morning he sent her two Tweets, promising to meet up when he’s in Portland.

so @scooterbraun just showed me something really powerful…about to do these interviews but gotta do this first…—
Justin Bieber (@justinbieber) June 06, 2012

MEGAN you stay strong for me and I'm gonna make sure we meet when i come to Portland. Love you and Thank You – kptv.com/story/18712884…—
Justin Bieber (@justinbieber) June 06, 2012

And Hamm will have new music to keep her happy soon. Bieber’s new album Believe is out in two weeks and his latest, “All Around the World” was just released this week.

Less than #2WEEKS to go – #BELIEVE—
Justin Bieber (@justinbieber) June 06, 2012

-Courtney E. Smith, CBS Local