One of every 400 African-American children and one of every 1,250 Hispanic American children is born with sickle cell anemia that can result in recurrent, painful episodes called "sickle cell crises." The disease also results in increased vulnerability to infections, organ damage, and early death. A child with sickle cell can develop a painful crisis at any time. The pain can last for days to weeks and is often severe enough to require hospitalization. The unpredictability of these pain events and their recurrent nature contribute significantly to the suffering of these children.