Diagnosis of beta-thalassaemia carriers in the Sultanate of Oman

Background: Haemoglobinopathies are a major cause of morbidity in the Sultanate of Oman and premarital screening is being encouraged in order to reduce the number of affected births. The identification of β-thalassaemia carrier status is an essential prerequisite of any screening programme. However, the level of Haemoglobin (Hb) A₂, which is used to detect β-thalassaemia carriers, can be affected by other factors including iron deficiency, concurrent a thalassaemia and the type of DNA mutation present. Objectives: The following study was undertaken to ascertain if the Hb A₂ level is an appropriate tool for the identification of β-thalassaemia carriers in the Omani population. Method: Hb A₂ was measured by high performance liquid chromatography (HPLC) in 160 obligate carriers of β-thalassaemia. 158 subjects had Hb A₂ levels above 3.5% indicating β-thalassaemia trait. Two subjects had slightly lower levels and were found to be iron deficient. After therapy both these subjects' Hb A₂ levels increased to above 3.5%. Conclusion: In the absence of iron deficiency, Hb A₂ is an accurate marker for the presence of β-thalassaemia trait in the Sultanate of Oman.