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| CONTACT | |
External | |
| HEMATOLOGY | |
Normal in the heterozygote | |
| ELECTROPHORESIS | |
Hb X moves like Hb S on cellulose acetate and starch gel at alkaline pH; slightly slower than Hb A at acidic pH on citrate agar | |
| CHROMATOGRAPHY | |
Hb A and Hb X can be separated by anion exchange HPLC | |
| STRUCTURE STUDIES | |
Tryptic digestion; separation of peptides by fingerprinting; reversed phase HPLC; amino acid analysis; sequencing | |
| DNA ANALYSES | |
Not reported; presumed mutation GAC->AAC; alpha2 or alpha1 | |
| FUNCTIONAL STUDIES | |
Normal oxygen affinity, Bohr effect, and cooperativity | |
| STABILITY | |
Normal | |
| OCCURRENCE | |
Found in a few Japanese and Black families | |
| OTHER INFORMATION | |
Quantity in heterozygotes 12-24%; Hb M-O occurred in one Black family together with Hb G-Philadelphia [alpha68(E17)Asn->Lys] that is linked to alpha-thal-2 (-3.7 kb). In one child both alpha chain variants (plus an alpha-thal-2 heterozygosity) and Hb A occurred together; this is a second observation of two alpha chain variants and normal alphaA in one individual, again supporting duplication of the alpha locus. The quantities in this child were 58% Hb G + Hb M-O and 42% Hb A (Ref. 3). | |
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| REFERENCES |
| 1. | |
Ohba, Y., Miyaji, T., Matsuoka, M., Takeda, I., Fukuba, Y., Shibata, S., and Ohkura, K.: Hemoglobin, 1:383, 1977. | |
| 2. | |
Moo-Penn, W.F., Johnson, M.H., and Therrell, B.L., Jr.: Hemoglobin, 2:71, 1978. | |
| 3. | |
Zeng, Y-T., Headlee, M.E., Henson, J., Lam, H., Wilson, J.B., and Huisman, T.H.J.: Biochim. Biophys. Acta, 707:206, 1982. | |