Teen Mom: The Next Chapter star Leah Messer’s daughter reached a major milestone in her health battle in 2023. The Sun reported that Aliannah Sims (known as Ali), who Leah shares with ex-husband Corey Simms, was diagnosed with Titin Myotonic Muscular Dystrophy and sometimes relies on a wheelchair due to her muscle weakness.

Over 10 years after Ali was diagnosed with a rare and incurable form of muscular dystrophy, Leah revealed her positive progress. “Not only has she gotten stronger physically,” Leah told E! News, “she’s also gotten stronger mentally.”

Inside Leah Messer’s Daughter’s Medical Issues

Leah Messer’s daughter Ali Simms has been under a doctor’s care since her 2014 diagnosis of muscular dystrophy. Her condition was first revealed on 16 & Pregnant, and MTV reality show fans have since followed her health journey on social media.

The reality TV star has remained hopeful about her daughter’s future and has avoided some of the worst-case predictions connected to Ali’s disease.

The former teen mom said, “Muscular dystrophy, it is a degenerative progressive disease. So we don’t know what the future really looks like. But I know that we’re going to enjoy every single moment now and continue to make memories and make the best of it.”

ScreenRant reported that in an episode of Teen Mom 2, Leah opened up about providing Ali with school aid. In another episode, Leah opened up to her sister about the tests Ali underwent. “They did testing on everything, her heart, her lungs,” she told Victoria after Ali began suffering a shortness of breath. “She does have allergies that are restricting her airways and causing asthma.”

Leah Messer’s Reality TV Appearances:

Ali’s teachers had explained that the girl was falling down frequently at school, and was struggling to open her food during lunchtime. “She needs somebody with her, by her side, at all times.”

“I’m fighting for Ali — I’m going to do everything that she needs done,” Leah said. “We wanted her to be independent, and at the same time things are becoming progressive.”

Here’s How Horse Riding Has Helped Ali

Leah Messer has credited Ali’s commitment to equine therapy for the improvement in her strength and weight. In March 2022, she told PEOPLE how happy the doctors were with her daughter’s progress.

Leah explained that the medical professional “gave a lot of credit to her love, hard work, and dedication to reaching horseback riding goals that she sets for herself. Reflex is still the same but strength is better, pulmonary is better, weight, and growth chart is better than it has ever been.”

The family purchased their first horse in August 2014. Leah explained in a social media post that she had invested in a child’s handicapped saddle so that her daughter could enjoy it. After backlash online, she said, “The horse was given to the girls and for Ali to use for therapeutic riding from her grandparents.”

The Sun reported that Leah posted videos of her daughter in February 2023, where she talked about her future goals. “I’m going to have a horse barn and be an equestrian and then I have like three dog breeds – two or three – a St. Bernard, a Cane Corso, or an English Mastiff, and then two cats.”

Leah Messer Admits It Was ‘Lonely’ After Ali’s Diagnosis

Leah Messer opened up about the stress of her daughter Ali being diagnosed with muscular dystrophy. In her memoir, Hope, Grace & Faith, the reality star “knew the moment Ali was born” that there was something the medical team was not telling her about Ali.

She explained how Aleeah was “reaching developmental milestones” when Ali “just didn’t seem to have the strength.” By Ali’s first birthday, she couldn’t bear any weight on her legs, which led to her and their father, Corey Simms, meeting different specialists.

Leah explained how the road to getting a diagnosis for Ali was “long and lonely” for the family, as she felt “helpless” all the time. She explained in her memoir that “only a handful of adults around the world with the same type of muscular dystrophy, and Ali was the first child ever to be diagnosed.”

She added that having Ali tested was like having their “hearts ripped out of our bodies, especially when she had to be sedated for the MRIs and the muscle biopsy.”

How Ali Coped Growing Up With Muscular Dystrophy

Ali, Aleeah, and their youngest sister, Adalynn, appeared in the second season of Teen Mom: The Next Chapter in 2024, where the family had a candid conversation about Ali’s muscular dystrophy.

Leah and Ali’s twin Aleeah had a heart-to-heart after the Teen Mom star asked if “Ali fully accepts she has muscular dystrophy.”

“No, I don’t think she realizes that it’s there. And that she thinks that she can do everything that we do. But when it comes down to it, she realizes that she can’t. So I think that tears her down,” Aleeah responded.

Aleeah admitted that she thinks her sister has declined the use of a wheelchair because she does not want to feel “different.” Leah understood that the family should help Ali feel comfortable about her disabilities. Leah also admitted she wanted Aleeah to not feel like her sister was a burden and that she had to focus on her own life.

In May 2024, Leah spoke to PEOPLE about her “cringe conversations” with her daughters on the second season of the Teen Mom spinoff. “I think this season, you also see all the talks I’ve had with my daughters over the years coming together, in a sense, and we see what they believe in and how they use their voices.”

Ali has not let her condition get in the way of growing up and into a bold teenager. Her grandfather Jeff, Corey Simm’s father, posted on Instagram in December 2024 that Ali was learning to drive.