Well that's something you don't see every day.
Holy Smokes: Guy Born Without Collarbones Can Clap His Shoulders

This is a video of 19-year old Corey Bennet demonstrating his unique shoulder-clapping talent as a result of being born without collarbones (he was actually born with Cleidocranial dysostosis, “that primarily affects the development of bones and teeth”). Pretty wild. Me? I was actually born with– “Let me guess, a detachable thumb.” How did you know?!