This national diagnosis and care protocol (PNDS) explains to the professionals concerned the optimal diagnostic and therapeutic management and care pathway of a patient suffering from acquired (AMA) or constitutional (AMC) bone marrow aplasia (BMA). It was drawn up by the reference center for acquired and constitutional bone marrow aplasia, using a methodology proposed by the French National Authority for Health (HAS). It has not been validated by the HAS, which did not participate in its development.