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Introduction: Several hemoglobin variants have electrophoretic behavior similar to hemoglobin S, which may lead to false diagnosis for sickle-cell disorders in newborn screening programs. A homozygous hemoglobin with S mobility was detected in two unrelated babies in Brazil., Methods: Isoelectric focusing and high-performance liquid chromatography assays, gene sequencing, and restriction fragment length polymorphism with AfeI were used to characterize the hemoglobin., Results: Hb Stanleyville-II and -α(3.7) /-α(3.7) type I deletion in the α-globin gene was diagnosed. Parents were heterozygous for both Hb Stanleyville-II and α-thalassemia. Hypochromia and microcytosis were probably due to the homozygous α-thalassemia., Conclusion: Stanleyville-II gene mutation is HBA2:c.237C>A, or C>G, and this information on the Globin Gene Server should be updated; AfeI test is a fast and accurate method to detect it; NBS programs should consider the possibility of Hb Stanleyville-II whenever IEF shows one band in the HbS position, and another one between S and C., (© 2011 Blackwell Publishing Ltd.)

Out of 128,326 newborns in the first 6-month period of a population-based screening program in Minas Gerais, Brazil, a second sample was obtained at the age of 6 months from 4,635 carriers of Hbs AS, AC, and AD which were detected by isoelectrofocusing. Discordance in results occurred in only 27 cases (0.6%): in seven there was a history of hemotransfusion; errors during pipetting or transcription of results occurred in seven cases; it was difficult to differenciate between Hbs S and D in eight patients; and the causes were not elucidated in five patients. The incidence of Hbs FS and FSC for the total population was 1:2,800 and 1:3,450, respectively. Isoelectrofocusing is a very reliable method for distinguishing AS, AC, or AD carriers from patients presenting with [corrected] variant hemoglobin and beta(+)-thalassemia combinations, and may be widely used in massive newborn screening programs.