Brooke Greenberg had rare condition in which she didn't age
                                
                                
                                    (Newser) -
                                    She was 20 years old, but Brooke Greenberg had a rare and puzzling ailment that essentially froze her in time as a toddler. Brooke, diagnosed with something called Syndrome X, died last week in suburban Baltimore, reports  Time . She had the physical and mental development of a 2-year-old, explains  ABC...