Thalassemia, inherited blood disorder in which hemoglobin is not adequately produced. Without hemoglobin—the red pigment in blood that carries oxygen through the body—children become sick and, with some varieties of the disease, die. This disorder most often affects people from the Mediterranean, along with Asian and Middle Eastern people as well as Black Americans. A mild form of the disease called thalassemia minor may cause a person to transmit the disorder to the next generation. With thalassemia major, or Cooley's anemia, a child may suffer various symptoms that often become fatal by early adulthood. Thalassemia intermedia is a serious but not always fatal variation of the disorder. Although not a cure, blood transfusions may relieve symptoms if administered on a regular basis.