Phenotypic expression of hemoglobins A₂, E and F in various hemoglobin E related disorders.
Study on the phenotypic expression of hemoglobin (Hb) A(2) and Hb E in Hb E disorders has been difficult due to the co-separation of Hb A(2) and Hb E in most Hb analysis assays. Because these two Hbs are separated on capillary electrophoresis, we studied phenotypic expression of Hbs A(2), E and F in various Hb E disorders using this system. This was done on 362 subjects with several Hb E disorders including heterozygous Hb E, homozygous Hb E, β-thalassemia/Hb E, δβ-thalassemia/Hb E, and Hb Lepore/Hb E and those of these disorders with several forms of α-thalassemia. Normal controls showed Hb A(2) of 2.7 ± 0.3%. Heterozygous Hb E and homozygous Hb E had elevated Hb A(2) i.e. 3.8 ± 0.3% and 4.8 ± 0.5%, respectively. Further elevations were observed for β(0)-thalassemia/Hb E (6.1 ± 1.9%) and β(+)-thalassemia/Hb E (7.1 ± 1.2%). Interestingly, no elevation of Hb A(2) was found in the δβ-thalassemia/Hb E, and Hb Lepore/Hb E (2.3 ± 0.3%) but higher Hb F levels were noted which could be useful diagnostic markers. The levels of Hb E were variable. Co-inheritance of these Hb E disorders with α-thalassemia were associated with lower outputs of Hb E and Hb F but the levels of Hb A(2) were not altered. Different phenotypic expression of Hb A(2), Hb E and Hb F could help in differential diagnosis of these Hb E related disorders commonly encountered in the regions where access to molecular techniques is limited.
Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
Nattaya
N
Sae-ung
Hataichanok
H
Srivorakun
Goonnapa
G
Fucharoen
Supawadee
S
Yamsri
Kanokwan
K
Sanchaisuriya
Supan
S
Fucharoen
D044466:Asian People / Q000235:genetics*; D016172:DNA Fingerprinting; D019075:Electrophoresis, Capillary; D005319:Fetal Hemoglobin / Q000235:genetics*; D015870:Gene Expression; D005838:Genotype; D005914:Globins / Q000235:genetics; D006443:Hemoglobin A2 / Q000235:genetics*; D006446:Hemoglobin E / Q000235:genetics*; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D010641:Phenotype; D017085:alpha-Thalassemia / Q000235:genetics*; D017086:beta-Thalassemia / Q000235:genetics*; D055538:delta-Thalassemia / Q000235:genetics*
D006455:Hemoglobins, Abnormal; D005914:Globins; D006443:Hemoglobin A2; D006446:Hemoglobin E; D005319:Fetal Hemoglobin; C037659:hemoglobin Lepore