[Application of the polymerase chain reaction (PCR) in the diagnosis of Hb S-beta(+)-thalassemia].
Isoelectric focusing of the hemolysate prepared from a two-year-old American black boy with microcytic hypochromia showed the presence of a high percentage (63.3%) of such Hb variant as Hb S, while the levels of Hb A, Hb F and Hb A2 were 20.0%, 12.7%, and 4.0%, respectively. The ratio of the non-alpha-chain to the alpha-chain of the biosynthesized globin chains was 0.49. The variant was identified as Hb S by amino acid analysis of the abnormal peptide (beta T-1) and digestion of DNA amplified by the polymerase chain reaction with enzyme Eco 81 I. This was further confirmed by DNA sequencing. DNA sequencing of a beta-gene without the beta s-mutation revealed a nucleotide change of T to C in the polyadenylation signal sequence AATAAA 3' to the beta-gene, resulting in beta(+)-thalassemia. These results are consistent with the existence of a beta s-gene and a beta(+)-thalassemia gene in trans.
Department of Biochemistry, Kawasaki Medical School, Kurashiki.
K
K
Harano
T
T
Harano
Y
Y
Kushida
S
S
Ueda
D002675:Child, Preschool; D006451:Hemoglobin, Sickle / Q000378:metabolism; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D013789:Thalassemia / Q000097:blood / Q000175:diagnosis*
D006451:Hemoglobin, Sickle