[Hemoglobin Korle-Bu [beta73(E17)Asp ->Asn]. First cases described in Spain]

Hemoblobin Korle-Bu [beta73(E17)Asp->Asn], also known as hemoglobin GACCRA, is frequent in African colour population. The interest of this work has been confirmed that hemoglobin Korle-Bu is a structural variant which mutation is located in the CD73 (GAT->AAT) of the exon 2 of beta gene and that this characterises has been made in the first cases found in Spanish population. Where to be carrier of African hemoglobins is less frequent.

Two unrelated families (4 subjects) from the same geographical area were studied because all of them shown an abnormal hemoglobin during a screening program of hemoglobinopathies in blood donors. Electrophoretic methods and ion exchange HPLC studied this hemoglobin. Globin chains are studied by reverse phase HPLC. Automatic sequencing carried out the molecular study.

In the electrophoretic study and by ion exchange HPLC was observed an abnormal hemoglobin. The study of globin chains by reverse phase HPLC revealed the presence of three peaks betaX, betaA y alpha. In all the cases, the P50 was increased. The molecular study by sequencing revealed the substitution GAT->AAT in the codon 73 of beta gene globin. This variant of haemoglobin is named hemoglobin Korle-Bu [beta73(E17)Asp->Asn].

This hemoglobin variant becomes important when it is associated with hemoglobin S or C because, although it is not associated with a clinical picture severe, when this hemoglobin is associated with another kind of alterations of hemoglobin molecule (thalassemias or hemoglobinopathies) the clinical could be more severe. So, it is important its genetic characterization for the diagnoses of the serious forms.