|
|
|
|
| CONTACT | |
External | |
| HEMATOLOGY | |
Mild microcytosis in heterozygotes; normal to mild anemia, reduced red cell survival, reduced MCV, target cells, reduced osmotic fragility in homozygotes | |
| ELECTROPHORESIS | |
Hb E and Hb A can readily be separated at alkaline pH but not at acidic pH; Hb E moves much slower than Hb A, just ahead of Hb A2 and Hb C | |
| CHROMATOGRAPHY | |
Hb E and Hb A separate at cation and anion exchange chromatography; it elutes with Hb A2 in several chromatographic systems, including cation exchange HPLC | |
| STRUCTURE STUDIES | |
Tryptic digestion; fingerprinting; cation exchange chromatography; amino acid analysis; sequencing | |
| DNA ANALYSES | |
A GAG->AAG mutation at codon 26 | |
| FUNCTION STUDIES | |
Purified Hb E has a normal oxygen affinity | |
| STABILITY | |
Mildly unstable; it is sensitive to oxidative stress | |
| OCCURRENCE | |
Widespread in the Far East; has been observed in combination with various Hb variants, including Hb S, Hb C, Hb D, Hb I, etc., and with different beta-thal alleles | |
| OTHER INFORMATION | |
Quantity in the heterozygote with four alpha genes (alphaalpha/alphaalpha) ~30%; Hb E is one of the most frequently studied variants; references can be found in the listed monographs | |
|
|
|
|
| REFERENCES |
| 1. | |
Weatherall, D.J. and Higgs, D.R., editors: The Haemoglobinopathies, Bailliere's Clinical Haematology, Vol. 6, W.B. Saunders Company, London, 1993. | |
| 2. | |
Miller, D.R. and Baehner, R.L., editors: Blood Diseases of Infancy and Childhood, 7th edition, Mosby-Year Book, Inc., St. Louis, MO, 1995. | |