MUTATION | Codon 60 (T->A); GTG(Val)->GAG(Glu) | |||||||||||||||||||||||||||||||||||||
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AMINO ACID REPLACEMENT | See above (Hb Cagliari) | |||||||||||||||||||||||||||||||||||||
TYPE OF BETA-THAL | beta+ (abnormal betaX identified by IEF after labeling) | |||||||||||||||||||||||||||||||||||||
MECHANISM | Thalassemic features because of severely unstable Hb which is rapidly destroyed by proteolysis | |||||||||||||||||||||||||||||||||||||
IDENTIFICATION | Amplification of the beta-globin gene; sequencing | |||||||||||||||||||||||||||||||||||||
HEMATOLOGY IN HETEROZYGOTE(S) | Found in a patient with thalassemia intermedia with normal parents: Hb 6.0 g/dl; splenectomy; thalassemia-like bone changes; improved after splenectomy. For hematological data see below. After splenectomy large, solitary, inclusion bodies in a limited number of RBCs | |||||||||||||||||||||||||||||||||||||
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HEMATOLOGY IN HOMOZYGOTE(S) | None | |||||||||||||||||||||||||||||||||||||
OCCURRENCE | In a Sardinian patient | |||||||||||||||||||||||||||||||||||||
HAPLOTYPE | Not done | |||||||||||||||||||||||||||||||||||||
FOUND IN COMBINATION WITH ABNORMAL HB(S) | None | |||||||||||||||||||||||||||||||||||||
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) | None | |||||||||||||||||||||||||||||||||||||
OTHER INFORMATION | The Hb variant is synthesized at a normal rate but is rapidly broken down (highly unstable) resulting in markedly ineffective erythropoiesis |
REFERENCES | |||
1. | Podda, A., Galanello, R., Maccioni, L., Melis, M.A., Rosatelli, C., Perseu, L., and Cao, A.: Blood, 77: 371, 1991. |