Hemoglobins F, A(2), and E levels in Laotian children aged 6‐23 months with Hb E disorders: Effect of age, sex, and thalassemia types

INTRODUCTION: Determination of hemoglobins (Hbs) F, A(2,) and E is crucial for diagnosis of thalassemia. This study determined the levels of Hbs F, A(2,) and E in children aged 6‐23 months and investigated the effect of age, sex, and types of thalassemia on the expression of these Hbs. METHODS: A total of 698 blood samples of Laotian children including 272 non‐Hb E, 271 Hb E heterozygotes, and 155 Hb E homozygotes were collected. Hb profiles were determined using the capillary zone electrophoresis. Coinheritance of α‐thalassemia and the homozygosity for Hb E mutation were checked by PCR‐based assay. RESULTS: Children heterozygous and homozygous for Hb E had significantly higher Hb F and A(2) levels than non‐Hb E children (median Hb F = 1.1% for non‐Hb E group, 2.7% for Hb E heterozygotes, and 9.4% for Hb E homozygotes; median Hb A(2) = 2.6% for non‐Hb E group, 3.8% for Hb E heterozygotes, and 5.2% for Hb E homozygotes). The median Hb E levels were 21.9% for Hb E heterozygotes and 85.3% for Hb E homozygotes. Comparing within group, there was a statistically significant difference between children with and without an α‐gene defect for Hb A(2) and E, but not Hb F. Based on a multiple regression analysis, age and sex were significantly associated with the expression of Hb F and A(2) but not Hb E. CONCLUSIONS: Our findings can guide the development of a diagnostic approach to thalassemia in children aged 6‐23 months.