Molecular heterogeneity of beta-thalassaemia in the Japanese: identification of two novel mutations.
Five unrelated Japanese beta-thalassaemia genes, from one homozygote and four heterozygotes, have been systematically characterized using DNA polymorphism analysis, polymerase chain reaction, dot-blot hybridization and direct sequencing of amplified genomic DNA. Four different molecular defects were observed on three different beta-globin gene frameworks. One of these, the A----G mutation in the TATA box, a previously described mutation, was detected by dot-blot hybridization in one homozygote and one heterozygote with the beta-globin gene of framework 2. The second mutation is a C----T substitution at position 654 of IVS-2, the mutation commonly found in Chinese, which was associated with the framework 1 gene. Another two mutations, both associated with framework 3 genes, are novel ones; an amber mutation in codon 90 (GAG to TAG) and a frameshift (+G) insertion in codon 54, both of which cause a beta 0-thalassaemia phenotype by premature termination of the beta-globin chain synthesis.
Fucharoen
S
S
Research Laboratory for Genetic Information, Kyushu University, Fukuoka, Japan.
Katsube
T
T
Fucharoen
G
G
Sawada
H
H
Oishi
H
H
Katsuno
M
M
Nishimura
J
J
Motomura
S
S
Miura
Y
Y
Fukumaki
Y
Y
D000328:Adult; D005796:Genes / Q000235:genetics; D005914:Globins / Q000235:genetics; D006801:Humans; D015151:Immunoblotting; D007564:Japan; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D013789:Thalassemia / Q000235:genetics*
D005914:Globins