Hemoglobin Profiles and Hematologic Features of Thalassemic Newborns: Application to Screening of α-Thalassemia 1 and Hemoglobin E

Abstract

Context.—Thalassemia and hemoglobinopathies are major public health problems worldwide. To establish a cost-effective screening tool for newborns in regions where the incidence of these disorders is significant, study of the hemoglobin and hematologic features of normal and thalassemic newborns is necessary. Objective.—To study hemoglobin and hematologic characteristics of normal and various thalassemic newborns and to assess the effectiveness of simple screening methods for α-thalassemia 1 and hemoglobin E. Design.—Study was made of 402 cord blood specimens collected from unrelated Thai individuals. Hematologic parameters and hemoglobin profiles were determined. Thalassemia mutations were identified using polymerase chain reaction–related techniques. Results.—As many as 178 subjects (44.3%) were found to carry thalassemia genes with 18 different genotypes. All forms of α-thalassemia including double heterozygote for hemoglobin E and α-thalassemia showed significant reduction in hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin with increasing trend of red blood cell as compared with a non–α-thalassemic group. Although heterozygous hemoglobin E and β-thalassemia showed no hematologic difference from nonthalassemic group, heterozygous α-thalassemia 1 including those with hemoglobin E showed significant increase in hemoglobin Bart level. Conclusions.—Based on these findings, effective primary screening with 100% accuracy for α-thalassemia 1 and hemoglobin E in newborns in the region could be carried out using mean corpuscular volume less than 95 fL, mean corpuscular hemoglobin less than 30 pg, or hemoglobin Bart greater than 8.0% and hemoglobin E greater than 0.5%, respectively.

Prevalence and molecular characterization of alpha-thalassemia among newborns in Ardabil Province

“…But since using these parameters is more readily available in most laboratories, they can be used for primary screening of thalassemia in newborns. On the other hand, these parameters are highly predictive when MCV < 90fL and MCH<30pg (21)(22)(23). The values of MCV and MCH are strongly affected by the number of α-genes, cases with one α gene deletion have slightly decreased of these parameters and can be overlapped with normal values (24).…”

Diagnostic value of fetal hemoglobin Bart’s for evaluation of fetal α-thalassemia syndromes: application to prenatal characterization of fetal anemia caused by undiagnosed α-hemoglobinopathy

“…In the fetus and newborns, however, identification of Hb Bart’s is valid for detecting homozygous α 0 -thalassemia causing Hb Bart’s hydrops fetalis. In this most severe form of thalassemia, about 75% or more of Hb Bart’s, without Hb F and Hb A is usually observed [ 21 – 24 ]. This has been confirmed in Table 1 , in which fetuses with Hb Bart’s hydrops fetalis (n = 57) had 81.5 ± 3.6% Hb Bart’s as measured by capillary electrophoresis.…”