We report the clinical and laboratory findings in three unrelated families from southeastern Brazil with Sp αI/65 hereditary elliptocytosis (HE), including one homozygote and a patient presenting an elongated β-spectrin. In family 1, three patients presented the allele α-Lely in trails to the elliptocytogenic allele. In these three patients the blood smear showed pronounced elliptocytosis, poilkilocytosis and a few small red cell fragments instead of the mild elliptocytosis observed in their father, who did not present the polymorphism. In family 2 we describe one homozygote, with consanguineous parents presenting with anaemia, splenomegaly, severe poikilocytosis and elliptocytosis, budding, microspherocytes and numerous fragments in the blood smear. In family 3 we found an elongated βSp in a patient with Spα(I/65). The cause of the HE was the Spα(I/65), since the elongated βSp was not found in his brother, who also presented with HE and Spα(I/65). Apparently the abnormal βSp did not aggravate the HE, because both individuals had the same clinical and laboratory findings. However, the propositus presented a few more elliptocytes and poikilocytes than his brother, probably because the elongated β-spectrin may have disturbed the spectrin self-association. In fact, in the propositus an abnormal band was observed in the nondenaturing gels, just above the Sp dimer, probably as a result of the association of the abnormal βSp with the normal spectrin chains. In the family studied here, both brothers presented the allele αLely, but, as their mother was dead, it was not possible to determine the polymorphism transmission. However, the high number of poikilocytes observed in the blood smear of both cases suggests an association in trans with the Spα(I/65). 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