[Hemolytic anemia due to hemoglobin Evans in an Argentinean family].

Unstable hemoglobins are structural variants of the hemoglobin molecule, mostly originated by single amino-acid replacement in some globin chains. These changes affect molecule stability, leading to loss of solubility, precipitation, and cellular lysis. Patients carrying these unstable hemoglobins may present mild to severe chronic hemolytic anemia. Hemoglobin Evans is an unstable variant originated by replacement of valine with methionine at position 62 of the α-globin chain. We have identified this variant in a girl with an acute hemolytic crisis associated to pharyngitis, as well as in two of her family members. This is the third case of hemolytic anemia due to hemoglobin Evans reported in the literature.