Causes of other types of aplastic anemia may be chemotherapy , radiation therapy , toxins , drugs, pregnancy , congenital disorder, or systemic lupus erythematosus .
Symptoms arise as the consequence of bone marrow failure.
Low white blood cell counts, or neutropenia, causes an increased risk of infection. Low platelet counts, or thrombocytopenia , results in bleeding of mucus membranes and skin. The disease may be acute or chronic , and is always progressive. Risk factors are unknown. The incidence is 2 out of 1 million people.