Anemia due to failure of the bone marrow to produce red and white blood cells as well as platelets. Aplastic anemia frequently occurs without a known cause. Known causes include exposure to chemicals (for example, ben- zene, toluene in glues, insecticides, solvents), drugs (for example, chemotherapy drugs, gold, seizure medications, antibiotics), viruses (for instance, HIV, Epstein-Barr), radiation, immune conditions (for example, systemic lupus erythematosus, rheumatoid arthritis), pregnancy, paroxysmal nocturnal hemo- globinuria, and inherited disorders (for example, Fanconi anemia).