Known and new Î´-globin gene mutations and other factors influencing Hb A2 measurement in the Omani population.

[alpha-thalassemia]

Although Î´-thalassemia (Î´-thal ) is not categorized as a severe disease , it is essential to know the molecular spectrum of the Î´ gene mutations frequently occurring in specific areas , particularly if these areas are characterized by a high rate of Î²-thalassemia (Î²-thal ) such as Oman . This is because coinherited Î´-globin gene defects can interfere with the basic diagnosis of a Î²-thal carrier when this is based upon the measurement of the Hb A 2 only . Because of that , we have investigated 33 patients with low Hb A 2 levels , collected from different hospitals in Oman . Some cases had a second Hb A 2 fraction , while others had only significantly lower Hb A 2 levels . Among these patients , 20 did carry a Î´-globin gene mutation , the rest were carriers of Î± thalassemia (Î±-thal ) defects or could be iron depleted or both . In total , eight different known mutations and two novel Î´ variants were found . The characterization of the Î´-globin gene mutation spectrum will improve carrier diagnostics and genetic counseling in the Omani population screened for Î²-thal .