The Corfu δ0β+ thalassemic allele is a unique thalassemic allele consisting of the simultaneous presence in cis of a deletion of the δ-
globin (
Hemoglobin Subunit Delta, HBD) and a single
nucleotide variant in the β-
globin gene (
Hemoglobin Subunit Beta, HBB). The allele has, so far, been described in individuals of Greek origin. The objectives of the study are to ascertain the prevalence of the Corfu δ0β+ allele in comparison to other β-
thalassemia variants encountered in Greece using our in-house data repository of 2558 β-
thalassemia heterozygotes, and to evaluate the hematological phenotype of Corfu δ0β+ heterozygotes in comparison to heterozygotes with the most common β+- and deletion α0-
thalassemia variants in Greece. The results of the study showed a relative incidence of heterozygotes with Corfu δ0β+ at 1.56% of all β-thalassemic alleles, and a distinct hematological phenotype of the heterozygotes characterized by microcytic,
hypochromic anemia with normal levels of HbA2 (
Hemoglobin A2) and elevated HbF (
Hemoglobin F) levels. The application of a specific methodology for the identification of the Corfu δ0β+ allele is important for precise prenatal and antenatal diagnosis programs in Greece.