Has anyone noticed Apple Bloom appears to have an unusually small uvula and unusually high palate? She’s also unusually weak for an earth pony (though to her credit she was supposed to be 7 here), is implied to have a family history of being tall, and potentially has poor stamina potentially pointing to cardiovascular problems, among other things. All of these are symptoms of Marfan Syndrome though aren’t exclusive to it. If one episode has her go blind, suffer cardiac arrest or an aortal dissection, break several bones, or be too weak to help with the harvest despite the other crusaders being perfectly capable, then it’s safe to assume she has Marfan Syndrome.