Congenital aplastic anemia, also known as Fanconi syndrome, is an autosomal recessive disorder characterized by multiple congenital anomalies in addition to complete blood cell reduction. The symptoms of congenital aplastic anemia include pale skin and mucous membranes, severe anemia, and acute anemia. Why do these symptoms occur? Causes: The in vitro production of BFU-E and CFU-E by the patient’s blood and bone marrow single nucleated cells has been studied and the etiology can be classified into six groups: 1. No red lineage progenitor cell growth, severely reduced bone marrow proliferation, dependent on blood transfusion for maintenance, and ineffective to androgens. 2, Similar to the above group, but only BFU-E does not grow. 3, BFU-E is reduced, androgens are effective, myeloproliferation is reduced or severely reduced, and blood transfusion is not required. 4.CFU-E and BFU-E are lower than normal, with reduced myeloproliferation, no androgen therapy and no blood transfusion. 5, Stable disease, mild anemia and/or thrombocytopenia and/or macrocytosis, slightly reduced BFU-E. 6, Normal blood picture with normal or slightly reduced BFU-E and CFU-E, no treatment required. It indicates that FA patients have a very inconsistent clinical presentation, between normal and very abnormal.