Hemoglobin (Hb) variants involving alpha-chains are less common in the global population than Hb variants resulting from beta-chain alterations. Generally, alpha-chain Hb variants are caused by point mutations affecting alpha-1 and/or alpha-2 genes of the alpha-globin cluster (HBA1 and HBA2). In Brazil, the most prevalent alpha-chain Hb variant is Hb Hasharon. In this study, we present the first case of an Hb Val de Marne variant in the Americas, specifically in Brazil.
We describe a heterozygous case of Hb I-Philadelphia [alpha 16 (A14) LYS→GLU] in a blood donor from the Acre State Blood Bank, in the Brazilian Amazon region. We confirmed the mutation by electrophoretic and chromatographic methods and by DNA sequencing. A literature search showed that this is the first description of this alpha globin mutant in a Brazilian Caucasian group. We also emphasize the importance of the hemoglobin study in blood donors for the purpose of the genetic counseling and quality assurance of the blood to be transfused.