Microcytic anemia in a pregnant woman: beyond iron deficiency.

Sideroblastic anemias are a heterogeneous group of disorders characterized by anemia of varying severity and the presence of ringed sideroblasts in bone marrow. The most common form of inherited sideroblastic anemia is X-linked sideroblastic anemia (XLSA). In many XLSA patients, anemia responds variably to supplementation with pyridoxine (vitamin B6).