Relative quantitation of mRNA in beta-thalassemia/Hb E using real-time polymerase chain reaction

• Published in: Hemoglobin Vol. 24; no. 2; p. 105
• Main Authors: Watanapokasin, Y, Winichagoon, P, Fuchareon, S, Wilairat, P
• Format: Journal Article
• Language: English
• Published: England 01.05.2000
• Subjects: Adult; beta-Thalassemia - genetics; Frameshift Mutation; Globins - genetics; Hemoglobin E - genetics; Hemoglobins - metabolism; Humans; Linear Models; Polymerase Chain Reaction - methods; Reticulocytes; RNA Stability; RNA, Messenger - analysis; RNA, Messenger - blood
• ISSN: 0363-0269
• DOI: 10.3109/03630260009003429

beta-Thalassemia and Hb E patients, with seemingly identical genotypes, have a remarkable variability in severity. Reduction in red cell survival in beta-thalassemia is correlated with the amount of intracellular unmatched alpha-globin chains. However, it was only recently realized that mRNA, whose translation is prematurely terminated, is also unstable. No systematic attempts have been made to investigate mRNA stability in beta-thalassemia arising from nonsense mutations located upstream from the normal termination codon. In this study, one-step real-time polymerase chain reaction has been employed to compare the levels of alpha- and beta-globin mRNA in reticulocytes from beta-thalassemia/Hb E subjects. The results showed the highest alpha/beta-globin mRNA ratio (median = 5.70, n = 13) in frameshift codons 41/42 (-TTCT)/Hb E individuals compared to normal subjects (median = 1.02, n = 6), or those with Hb E trait (median = 2.15, n = 8). In addition, there was a concomitant increase in the alpha/beta-globin mRNA ratio with decrease in hemoglobin level, i.e., increase in severity. The difference in the ratio among beta-thalassemia/Hb E patients with the same genotype may be attributed to individual variations of efficiency in betaE-globin mRNA splicing and in the destruction of prematurely terminated mRNA.