Yes, it could be based on real medical cases. Many stories draw inspiration from real - life medical situations to highlight ethical, scientific, or human - interest aspects.
I'm not entirely sure specifically which 'Mantle Twins True Story' you're referring to. There could be many stories about twins with the last name Mantle. It might be a personal family story, or perhaps something more well - known in a local community.
Yes, it could be a true story depending on the context. There might be an individual named Beverly Sutphin in real life around whom a story has been based. However, without more specific information, it's hard to be certain.
Billy Elliot is based on a true story to a certain extent. It incorporates real elements but may have fictionalized parts to enhance the drama and entertainment value.