Identification of a novel δ-globin gene mutation in an Iranian family.

δ-Thalassemia (δ-thal) has no clinical symptoms, but its coinheritance with ß-thal may cause misdiagnosis, especially in countries with a high prevalence of ß-thal where prevention programs have been implemented. The molecular basis of most ß-thal syndromes have been defined, while the spectrum of mutations causing δ-thal have not been well characterized. A couple was referred to us for thalassemia molecular screening. Since she had rather low values of Hb A2 and normal Hb F, her δ-globin gene was amplified and directly sequenced. We found two different mutations on her δ-globin genes: HBD: c.92+5G>T/HBD:c.428C>A. The c.92+5G>T mutation has not been previously reported. Two different mutations in trans may explain the reduced Hb A2 level.