Application of the polymerase chain reaction (PCR) in the diagnosis of Hb S-beta (+) -thalassemia
Harano, K.; Harano, T.; Kushida, Y.; Ueda, S.
Rinsho Byori. Japanese Journal of Clinical Pathology 39(8): 835-840
1991
ISSN/ISBN: 0047-1860 PMID: 1920879 Document Number: 385516
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.