First report on the co-inheritance of beta-globin IVS-I-5 (G-->C) thalassemia with delta globin CD12 {Asn-->Lys (AAT-->AAA)}HbA₂-NYU in Iran.

Abstract : BACKGROUND: Co-inheritance of β- and δ-globin mutations in Iran is not uncommon. This situation may interfere with correct diagnosis and genetic counseling of α- and β-thalassemia in screening programs. Here we report the co-inheritance of β- and δ-globin gene mutations in an individual with microcytosis, hypochromia and a normal hemoglobin A₂ (HbA₂) level. METHODS: Genomic DNA extraction, amplification refractory mutation system (ARMS) polymerase chain reaction and direct DNA sequencing of δ- and β-globin genes were exploited for detection of the mutations in these two genes in an individual with low hematological indices and normal HbA₂. RESULTS: ARMS-PCR technique revealed the β(+) IVSI-5 (G to C) mutation and direct DNA sequencing of the δ-globin gene detected a previously reported delta codon 12 (AAT-->AAA) HbA2-NYU. This study reports HbA2-NYU in association with the β IVSI-5 (G to C) mutation in Iran. DISCUSSION: This report emphasizes that normal HbA₂ expression in a β-goblin carrier is due to mutation in the δ-globin gene and may cause misdiagnosis of thalassemia.