A mаn оf Mediterrаneаn ancestry gоes tо his doctor with the following symptoms. He is very tired all of the time. He has difficulty catching his breath after even mild exercise. His doctor orders the following tests: CBC, hematocrit, differential WBC count. The tests show immature erythrocytes, fragile erythrocytes, and less than 2 million RBCs per cubic millimeter. What would be a tentative diagnosis and suggested treatment?