Effect of Iron Deficiency on the Phenotype of β-Thalassaemia Trait.

The objective of this study was to determine the effect of iron deficiency on Hb-A2 level in β-thalassaemia trait and to determine the frequency of individuals with β-thalassaemia trait who could be missed due to concomitant iron deficiency. A total of 120 patients were studied, out of which 23 were iron deficient (serum ferritin < 20 ng/ml). Mean Hb-A2 in the iron deficient individuals was 4.1 ± 0.47% as compared to 5.1 ± 0.58% in the remaining 97 individuals without iron deficiency (p < 0.001). In the 120 individuals with β-thalassaemia trait, mean Hb-A2 was 5.8% with range 3 - 6.8% and confidence interval was 95%. In 2 individuals with β-thalassaemia trait, Iron deficiency was observed and showed Hb-A2 less than 3.5%. These could have been missed while screening by Hb-A2 estimation alone. Co-existence of Iron deficiency and β-thalassaemia trait may mask the diagnosis of beta thalassaemia trait and such individuals can be missed during screening by Hb-A2 estimation alone.