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We've been anxious about the health of Teen Mom 2's Aliannah Hope for years, but fans have finally been clued in about this little lady's mysterious developmental disorder. Apparently,  Leah Messer's daughter has a rare form of muscular dystrophy, a congenital condition that affects the skeletal muscles.

MTV viewers have seen Ali struggle with learning to walk, which makes perfect sense considering that her condition directly affects the muscles. According to the U.S. National Library of Medicine, Ullrich congenital muscular dystrophy is usually severe, and Ali will eventually have to use a wheelchair once her muscles can no longer support her weight. It's also possible that her respiratory muscles could weaken, which could make it difficult for her to breathe.

Muscular dystrophy is relatively rare and only occurs in 1 of 1 million people, and it's likely that both Leah and her husband, Corey Simms, had a copy of a mutated recessive gene. The good news? According to Cleveland Clinic, Ali's condition can be managed through physical therapy (which she has regularly), occupational therapy, surgery, cardiac care, and respiratory care — including the use of a ventilator to help with breathing.

Hopefully, Ali won't need anything this invasive for a while — as as far as we know she's still able to walk on her own! (Though Leah and her husband, Jeremy, are looking for a handicap accessible home.)

Are you surprised by Ali's diagnosis? Tell us your thoughts in the comments.

Source: U.S. National Library of Medicine / Cleveland Clinic