Coinheritance of Hb Bristol-Alesha [β67(E11)Val→Met; HBB: c.202G>A] and the α212 Patchwork Allele in a Brazilian Child with Severe Congenital Hemolytic Anemia |
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Authors: | Gisele A Pedroso Elza M Kimura Magnun N N Santos Dulcinéia M Albuquerque Jucilane L H Ferruzzi Susan E Jorge |
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Institution: | 1. Hemoglobinopathies Laboratory, Department of Clinical Pathology, School of Medical Sciences, State University of Campinas (UNICAMP), Campinas, S?o Paulo, Brazil;2. Hematology and Hemotherapy Center, State University of Campinas (UNICAMP), Campinas, S?o Paulo, Brazil;3. University Hospital, Federal University of Grande Dourados (UFGD), Dourados, Mato Grosso do Sul, Brazil |
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Abstract: | Hb Bristol-Alesha HBB: c.202G>A; β 67 Val>Met] is a rare structural variant of hemoglobin (Hb) resulting from a GTG>ATG substitution at codon 67 of the β-globin gene that leads to the replacement of valine by methionine in the corresponding position of the β-globin chain. The methionine residue is subsequently modified to aspartic acid β67(E11)Val-Met→Asp], possibly by autoxidation mechanisms. This substitution prevents normal non-polar binding of Val67 to the heme group, resulting in molecular instability and severe hemolysis. We identified Hb Bristol-Alesha (in the heterozygous state), as the cause of severe congenital hemolytic anemia in an 11-month-old girl of mixed (native Indian and European) ethnic origin from the Midwestern region of Brazil, whose parents were clinically and hematologically normal. The mutation on the β-globin gene was found to have been coinherited with the α212 patchwork allele. |
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Keywords: | α212 Patchwork allele Brazilian population congenital hemolytic anemia Hb Bristol-Alesha unstable Hb variant |
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