“U.S. researchers said Wednesday they have found a way to reverse Down syndrome in newborn lab mice by injecting an experimental compound that causes the brain to grow normally. The team at Johns Hopkins University used lab mice that were genetically engineered to have extra copies of about half the genes found on human chromosome 21, leading to Down syndrome-like conditions such as smaller brains and difficulty learning to navigate a maze. ‘It worked beautifully,’ said lead author Roger Reeves of the Johns Hopkins University School of Medicine. ‘We were able to completely normalize growth of the cerebellum through adulthood with that single injection.'”
http://www.rawstory.com/rs/2013/09/04/johns-hopkins-researchers-reverse-down-syndrome-in-mice/