This video is unavailable because we were unable to load a message from our sponsors. If you are using ad-blocking software, please disable it and reload the page. Embed Code Restart Playing WATCH MORE VIDEOS FROM THIS EPISODE > Sarah, 17, has neurofibromatosis or NF, a genetic disorder that has caused a large tumor to grow on the right side of her face. Pediatrician Dr. Jim Sears explains what causes Sarah's condition. ShareTweet