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| ALSO KNOWN AS | |
Istanbul | |
| CONTACT | |
Heme contact; proximal histidine | |
| HEMATOLOGY | |
Hemolytic anemia of variable severity in the heterozygote | |
| ELECTROPHORESIS | |
Hb X and Hb A separate at alkaline pH; Hb X moves between Hb S and Hb C | |
| CHROMATOGRAPHY | |
Hb X can be isolated by DEAE-Sephadex chromatography; Hb X elutes before Hb A | |
| STRUCTURE STUDIES | |
Tryptic digestion of AE-betaX chain; separation of peptides by fingerprinting or by cation exchange chromatography; amino acid analysis; sequencing | |
| DNA ANALYSES | |
Not reported; presumed mutation CAC->CAA or CAG at codon 92 | |
| FUNCTION STUDIES | |
Normal oxygen affinity for whole cells; increased oxygen affinity for 'stripped' pure Hb X; no Bohr or 2,3-DPG effects; decreased cooperativity | |
| STABILITY | |
Unstable; dissociates into dimers, particularly at higher pH | |
| OCCURRENCE | |
Found in a young French male and in a Turkish male, but not in their parents | |
| OTHER INFORMATION | |
Variant carries heme only on its alpha chains; this affects quantitation of the abnormal Hb; quantity in heterozygotes estimated at 25% which is likely too low; high level (20%) of Hb F present in the French patient with the least severe disease | |
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| REFERENCES |
| 1. | |
Cohen-Solal, M., Thillet, J., Gailardon, J., and Rosa, J.: Eur. J. Clin. Biol. Res., 17:988, 1970. | |
| 2. | |
Aksoy, M., Erdem, S., Efremov, G.D., Wilson, J.B., Huisman, T.H.J., Schroeder, W.A., Shelton, J.R., Shelton, J.B., Ulutin, O.N., and Muftuoglu, A.: J. Clin. Invest., 51:2380, 1972. | |
| 3. | |
Beuzard, Y., Courvalin, J.Cl., Cohen-Solal, M., Garel, M.C., and Rosa, J.: FEBS Lett., 27:76, 1972. | |
| 4. | |
Rosa, J., Brizard, C.P., Gibaud, A., Beuzard, Y., Courvalin, J.Cl., Cohen-Solal, M., Garel, M.C., and Thillet, J.: Nouv. Rev. Fr. d'Hematol., 12:691, 1972. | |