<Tr> <Th> Synonyms </Th> <Td> Aplastic anaemia </Td> </Tr> <Tr> <Th> Specialty </Th> <Td> Oncology, hematology </Td> </Tr> <P> Aplastic anemia is a rare disease in which the bone marrow and the hematopoietic stem cells that reside there are damaged . This causes a deficiency of all three blood cell types (pancytopenia): red blood cells (anemia), white blood cells (leukopenia), and platelets (thrombocytopenia). Aplastic refers to inability of the stem cells to generate mature blood cells . </P> <P> It is more frequent in people in their teens and twenties, but is also common among the elderly . It can be caused by heredity, immune disease, or exposure to chemicals, drugs, or radiation . However, in about half the cases, the cause is unknown . </P>

​which condition is known as bone marrow depression anemia