A new δ chain variant, Hb A2-Tunis [δ46(CD5)Gly → Glu; HBD: c.140G>A], observed in a Tunisian family in association with a compound heterozygosity for Hb C [β6(A3)Glu → Lys; HBB: c.19G>A] β(0)-thalassemia [IVS-I-1 (β143, G>A); HBB: c.92+1G>A].

We describe a new delta-globin variant, Hb A(2)-Tunis [delta 46(CD5)Gly -> Glu; HBD: c.140G>A]. This hemoglobin ( Hb) variant displayed a faster electrophoretic mobility than normal Hb A(2) and was expressed at 3.2%. The molecular defect was characterized by DNA sequencing analysis. Hb A(2)-Tunis was found in a carrier of a beta(0) -thalassemia (beta(0)-thal) [IVS I-1 (beta 143, G4A); HBB: c.92 + 1G>A] and Hb C [beta 6(A3)Glu -> Lys; HBB: c.19G>A], presenting with a normal Hb A(2) level. Phenotype and genotype investigations revealed that the patient has a total Hb A(2) level of 7.1% that was expected for a beta-thalassemia (beta-thal) minor carrier.