MUTATION | Codon 127 (A->G); CAG(Gln)->CGG(Arg) | ||
---|---|---|---|
AMINO ACID REPLACEMENT | Gln->Arg (Hb Dieppe) | ||
TYPE OF BETA-THAL | Dominant inclusion body beta-thal trait | ||
MECHANISM | The mutation results in the synthesis of a highly unstable betaX chain which is removed from circulation by proteolysis, causing a beta-thal condition | ||
IDENTIFICATION | DGGE of amplified DNA fragments; sequencing | ||
HEMATOLOGY IN HETEROZYGOTE(S) | Chronic anemia (Hb 7.5 g/dl); occasional transfusion; splenomegaly; hemosiderosis; normal Hb A2; Hb F 18.0%; beta/alpha in vitro chain ratio 0.48 | ||
HEMATOLOGY IN HOMOZYGOTE(S) | None | ||
OCCURRENCE | In a 31-year-old French female | ||
HAPLOTYPE | Not reported | ||
FOUND IN COMBINATION WITH ABNORMAL HB(S) | None | ||
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) | None | ||
OTHER INFORMATION | Unstable Hb or betaX chain was not detected |
REFERENCES | |||
1. | Girodon, E., Ghanem, N., Vidaud, M., Riou, J., Martin, J., Galactéros, F., and Goossens, M.: Ann. Hematol., 65:188, 1992. |