Hemoglobin profiles and hematologic features of thalassemic newborns: application to screening of alpha-thalassemia 1 and hemoglobin E.

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 alpha-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 alpha-thalassemia including double heterozygote for hemoglobin E and alpha-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-alpha-thalassemic group. Although heterozygous hemoglobin E and beta-thalassemia showed no hematologic difference from nonthalassemic group, heterozygous alpha-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 alpha-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.