Hb A 2 -Pasteur-Tunis [δ59(E3)Lys→Asn, AA G →AA C ]: A New δ Chain Variant Detected by DNA Sequencing in a Tunisian Carrier of the Codon 39 (C→T) β 0 -Thalassemia Mutation

Abstract : We describe a new delta-globin variant, Hb A(2)-Pasteur-Tunis [delta 59(E3)Lys -> Asn, AAG -> AAC]. This hemoglobin (Hb) displayed an electrophoretic mobility faster than normal Hb A(2) and was expressed at 2.2%. The molecular defect was characterized, by DNA sequencing and confinned by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-designed protocol. Hb A(2)-Pasteur-Tunis was found in a carrier of a codon 39 (C -> T) beta(0)-thalassemia (thal), presenting with a normal Hb A(2) level. Phenotype and genotype investigations revealed that the total Hb A(2) level of the patient was that expected for a minor beta-thal (4.8%).