Molecular characterization of (δβ)°/β°-thalassemia and (δβ)°-thalassemia/hemoglobin E in Thai patients

Two cases of the Thai thalassemia patients with compound heterozygosities for (deltap) /beta-thalassemia and (deltabeta) -thalassemia/ hemoglobin E have been reported. The first case was a 8-yr-old boy who had the following hematologic data: Hb 6.5 g/dL, Hct 20.5%, MCV 70.4 fL, MCH 22.3 pg and MCHC 31.7 g/dL. Hemoglobin analysis revealed hemoglobin A2 and 91.7%, hemoglobin F. The second case. with Hb 13.9 g/dL. Hct 41.5%, MCV 69.5 fL, MCH 22.5 pg and MCHC 32.2 g/dL was a 16-yr-old male who had 46.1% hemoglobin E and 49.8% hemoglobin F. Globin gene analyses showed that both probands carried the same deletional type (deltabeta) -thalassemia tran) to the 4 bp deletions in codons 41/42 beta-thalassemia and to the beta(E)-globin gone, respectively. Polymerase chain reaction and DNA sequence analyses demonstrated that the 5' breakpoint of the (deltabeta)-thalassemia deletion was located in the second intron of the delta-globin gene and that the 3' breakpoint lay within a cluster of LI repetitive sequences at 4.7 kb 3' to the beta-globin gene.