Which anemia is defined by deficient numbers of red blood cell stem cells?

1. Aplastic anemia is the condition in which there are deficient numbers of red cell stem cells. 2. It is often inherited, or it may be triggered by radiation, medication, chemotherapy or infection. 3. Because the defect is upstream at the stem cell, no amount of dietary iron or vitamin repair will correct it. 4. Megaloblastic and pernicious anemias are vitamin problems and sickle cell anemia is a hemoglobin gene problem, so none of them is a stem cell shortage. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 18 "The Cardiovascular System: Blood", section 18.3 Erythrocytes_