MUTATION | Initiation codon ATG->GTG | ||
---|---|---|---|
AMINO ACID REPLACEMENT | Met->Val | ||
TYPE OF BETA-THAL | beta° | ||
MECHANISM | Defective mRNA translation; absence of beta chain production; initiation changed to codons 21-22; termination at codons 60-61 (TGA) | ||
IDENTIFICATION | Cloning of the amplified beta-globin gene; DNA sequencing; dot-blot analysis with allele specific probes; NcoI digestion (a restriction site is lost); ASO | ||
HEMATOLOGY IN HETEROZYGOTE(S) | Hb 9.1-11.6 g/dl; MCV 53-70 fl; MCH 16.1-21.7 pg; reticulocytes 3.1-8.2%; Hb A2 6.0-6.7%; Hb F 0.8-7.1%; alpha/beta ratio 0.47-0.55 | ||
HEMATOLOGY IN HOMOZYGOTE(S) | Not reported | ||
OCCURRENCE | Found in a few Japanese families | ||
HAPLOTYPE | Not done | ||
FOUND IN COMBINATION WITH ABNORMAL HB(S) | Not reported | ||
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) | Not reported | ||
OTHER INFORMATION | It is surprising to see that some of the subjects are rather severely affected, alpha-globin gene status was not determined |
REFERENCES | |||
1. | Hattori, Y., Yamashiro, Y., Ohba, Y., Miyaji, T., Morishita, M., Yamamoto, Ku., Yamamoto, Ki., Narai, S., and Kimura, A.: Hemoglobin, 15:317, 1991. |