Hemoglobin E levels in double heterozygotes of hemoglobin E and SEA-type alpha-thalassemia.
Coinheritance of alpha-thalassemia and hemoglobin E (Hb E) is prevalent in Thailand, where the gene frequencies of thalassemia and hemoglobinopathies are high. Hb E carriers with, concomitant inheritance of alpha-thalassemia 1 are known to have a lower level of Hb E. In this study, we reviewed the Hb E levels in Hb E carriers, who either had or did not have Southeast Asian (SEA)-type alpha-thalassemia, in order to seek a Hb E level that may be used as a predictor for concomitant alpha-thalassemia carrier status. The Hb E levels as measured by microcolumn chromatography in 844 Hb E carriers detected during a prenatal screening program for severe thalassemia at Chiang Mai University Hospital were reviewed. Hb E levels ranged from 12.3-35.0% (23.3 +/- 3.1%) in 751 Hb E carriers without SEA-type alpha-thalassemia and from 11.6-32.0% (17.0 +/- 3.7%) in 93 concomitant Hb E and SEA-type alpha-thalassemia carriers. The difference was significant (p < 0.01). However, the absence of SEA-type alpha-thalassemia could not be predicted by the higher Hb E level alone, as 3% of double heterozygotes demonstrated a level of more than 25%. Our study confirms a lower Hb E level in double heterozygotes with Hb E and SEA-type alpha-thalassemia. Nevertheless, the difference does not provide sufficient discriminatory power for the reliable exclusion of alpha-thalassemia status.
Charoenkwan
Pimlak
P
Department of Pediatrics, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. pcharoen@mail.med.cmu.ac.th
Wanapirak
Chanane
C
Thanarattanakorn
Pattra
P
Sekararithi
Rattanaporn
R
Sae-Tung
Rattika
R
Sittipreechacharn
Somjai
S
Sanguansermsri
Torpong
T
D002845:Chromatography; D005260:Female; D006580:Genetic Carrier Screening; D005820:Genetic Testing / Q000379:methods; D006446:Hemoglobin E / Q000032:analysis* / Q000235:genetics*; D006801:Humans; D008297:Male; D011247:Pregnancy; D011295:Prenatal Care / Q000379:methods; D011296:Prenatal Diagnosis; D012372:ROC Curve; D013785:Thailand / Q000453:epidemiology; D017085:alpha-Thalassemia / Q000097:blood* / Q000453:epidemiology / Q000235:genetics*
D006446:Hemoglobin E