MUTATION | G->A at codon 104 of the alpha2 gene; TGC->TAC | ||
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AMINO ACID REPLACEMENT | Cys->Tyr (Hb Sallanches) | ||
TYPE OF ALPHA-THAL | alpha-Thal-2 [alpha(T)alpha/alphaalpha] | ||
MECHANISM | The alpha-Sallanches chain, when combined with normal beta, forms an unstable dimer | ||
IDENTIFICATION | Amplification; cloning; sequencing; mRNA analysis by RT-PCR | ||
HEMATOLOGY IN HETEROZYGOTE(S) | Father and mother are heterozygous: Hb 13.8-14.0 g/dl; MCV 77-79 fl; MCH 24.0-25.5 pg; Hb A2 normal | ||
HEMATOLOGY IN HOMOZYGOTE(S) | Homozygous child (3 years old): Hb 8.5 g/dl; MCV 91 fl; MCH 26 pg; Hb A2 <1.0%; Hb H ~5.0%; splenomegaly; reticulocytosis; hemolytic episodes | ||
OCCURRENCE | In a French family | ||
HAPLOTYPE | Not determined | ||
FOUND IN COMBINATION WITH ABNORMAL HB(S) | Not reported | ||
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) | Not reported | ||
OTHER INFORMATION | Protein can be detected in small quantities by IEF and HPLC |
REFERENCES | |||
1. | Morlé, F., Francina, A., Ducrocq, R., Wajcman, H., Gonnet, C., Philippe. N., Souillet, G., and Godet, J.: Br. J. Haematol., 91:608, 1995. |