One-in-500 US blacks has sickle cell disease, but it also disproportionately affects Hispanics, Asians and those of Middle Eastern descent, experts say. An estimated 90,000 to 100,000 Americans are affected by the disease and more than 2 million people carry the gene that allows them potentially to pass it on to their children, Dr. Richard Drachtman, interim division chief of pediatric hematology/oncology at the Cancer Institute of New Jersey, said ahead of Saturday\'s start of Sickle Cell Disease Awareness Month. People who inherit one sickle cell gene and one normal gene have the sickle cell \"trait.\" \"Sickle cell trait is diagnosed with a simple blood test. People at highest risk for having sickle cell trait are those whose ancestors come from Africa, South or Central America, the Caribbean, Mediterranean countries, India and Saudi Arabia,\" Drachtman said in a statement. Drachtman said in sickle cell disease, the red blood cells become hard and sticky and come to resemble C-shaped sickles used as farm tools. The sickle cells die early, which causes a constant shortage of red blood cells. In addition, when these blood cells travel through small blood vessels, they get stuck and clog the blood flow, which can result in repeated episodes of severe pain, organ damage, serious infections or anemia, said Drachtman, who also is a professor of pediatrics at the University of Medicine and Dentistry, New Jersey-Robert Wood Johnson Medical School. Experts emphasize that people with sickle cell disease can live full lives and enjoy most of the activities that other people do if they undergo regular checkups, prevent infections and develop healthy habits.