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

Background: Co-inheritance of beta- and sigma-globin mutations in Iran is not uncommon. This situation may interfere with correct diagnosis and genetic counseling of alfa- and beta-thalassemia in screening programs. Here we report the co-inheritance of beta- and sigma-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 sigma- and beta-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 beta+ IVSI-5 (G to C) mutation and direct DNA sequencing of the beta-globin gene detected a previously reported delta codon 12 (AATaAAA) HbA2-NYU. This study reports HbA2-NYU in association with the beta IVSI-5 (G to C) mutation in Iran. Discussion: This report emphasizes that normal HbA2 expression in a beta-goblin carrier is due to mutation in the sigma-globin gene and may cause misdiagnosis of thalassemia.