Pure red cell aplasia (PRCA) is a developmental disorder of the red blood cell system only, with no changes in white blood cells and platelets. The immature red blood cells in the bone marrow stop at the directed stem cell and proerythroblast stages, and other immature red blood cells are extremely reduced, but the granulocyte system and megakaryocytes develop normally, and the life span of red blood cells is slightly shorter than normal. The anemia is normochromic, and the reticulocytes are reduced or absent. Children are more likely to get the disease than adults, and the disease type and prognosis are also different from those of adults. In 1936, Jaseph first reported a type of pure red blood cell aplasia in children, which was believed to be congenital or hereditary. Diamond and Blackfan described this disease as an independent disease in 1938, so it is also called Diamond-Blackfan anemia.