Ali Simms is doing great, despite her muscular dystrophy diagnosis. Ali Simms is doing great, despite her muscular dystrophy diagnosis. Corey Simms & Wife Miranda Begin Filming 'Teen Mom 2' Season 6 Years after being diagnosed with a rare form of the illness, known as Titin Muscular Dystrophy, the daughter of Teen Mom 2 stars Leah Messer and Corey Simms is enjoying the winter weather -- and running so much that her father had to slow her down.