Hb Seal Rock | alpha142, Term->Glu (TAA->GAA in alpha2); |
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modified C-terminal sequence is the same as | |
as Hb CS except that residue 142 is GLU |
HEMATOLOGY | Mild anemia with microcytosis and hypochromia in the heterozygote | ||
ELECTROPHORESIS | Hb X moves as two bands, slower than Hb A2 at alkaline pH | ||
CHROMATOGRAPHY | Hb X can be isolated by anion exchange chromatography; various alpha chain zones are obtained when Hb X is analyzed by reversed phase HPLC | ||
STRUCTURE STUDIES | Tryptic digestion of alphaX chain; separation of peptides by reversed phase HPLC; amino acid analysis; sequencing | ||
DNA ANALYSES | A TAA->GAA mutation at codon alpha142 (alpha2); the Hb Seal Rock abnormality can best be detected by sequencing of the alpha gene or by dot-blot analysis with specific probes | ||
FUNCTION STUDIES | Increased oxygen affinity | ||
STABILITY | Not reported | ||
OCCURRENCE | Found in a few Black families | ||
OTHER INFORMATION | When present in association with an alpha-thal-2 allele (3.7 kb deletion) a mild Hb H disease is observed |
REFERENCES | |||
1. | Bradley, T.B., Wohl, R.C., and Smith, E.J.: Clin. Res., 23:131A, 1975. | ||
2. | Fairbanks, V., Merritt, D., Rodgers, D., Thibodeau, S., Steinberg, M., Coleman, M., and Jones, R.: Blood, 86:657a (Suppl. 1), 1995. |