Objective: To compare the efficacy of routine haematological tests and molecular analysis in the diagnosis of double heterozygous α- and β-thalassaemia. Methods: Screening was carried out in extended family members from 125 families registered in the National Thalassaemia Registry, known to have both α- and β-thalassaemia carriers. Results: Eighty-three individuals from 59 families were identified to be double heterozygous for α- and β-thalassaemia only upon molecular analyses. Among 40 married individuals, 1 was at 25% risk for having β-thalassaemia major children and 6 for having Bart’s hydrops pregnancies. Conclusion: Molecular analysis must be used for the accurate diagnosis of double heterozygous α- and β-thalassaemia for proper risk ascertainment, especially in regions with a high prevalence of both types of thalassaemia.

Fucharoen S, Winichagoon P: Hemoglobinopathies in Southeast Asia: Molecular biology and clinical medicine. Hemoglobin 1997;21:299–319.
Schrier SL: Thalassemia: Pathophysiology of red cell changes. Annu Rev Med 1994;45:211–218.
Weatherall DJ, Provan AB. Red cells I: Inherited anaemias (see comments). Lancet 2000;355:1169–1175.
Weatherall DJ, Clegg JB: The Thalassaemia Syndromes. Oxford, Blackwell Science, 2001.
Kanavakis E, Wainscoat JS, Wood WG, Weatherall DJ, Cao A, Furbetta M, et al: The interaction of alpha thalassaemia with heterozygous beta thalassaemia. Br J Haematol 1982;52:465–473.
Melis MA, Pirastu M, Galanello R, Furbetta M, Tuveri T, Cao A: Phenotypic effect of heterozygous alpha and beta 0-thalassemia interaction. Blood 1983;62:226–229.
Rosatelli C, Falchi AM, Scalas MT, Tuveri T, Furbetta M, Cao A: Hematological phenotype of the double heterozygous state for alpha and beta thalassemia. Hemoglobin 1984;8:25–35.
Lam YH, Ghosh A, Tang MH, Chan V: The risk of alpha-thalassaemia in offspring of beta-thalassaemia carriers in Hong Kong. Prenat Diagn 1997;17:733–736.
Bowden DK, Vickers MA, Higgs DR: A PCR-based strategy to detect the common severe determinants of alpha thalassaemia. Br J Haematol 1992;81:104–108.
Lebo RV, Saiki RK, Swanson K, Montano MA, Erlich HA, Golbus MS: Prenatal diagnosis of alpha-thalassemia by polymerase chain reaction and dual restriction enzyme analysis. Hum Genet 1990;85:293–299.
Cai SP, Wall J, Kan YW, Chehab FF: Reverse dot blot probes for the screening of beta-thalassemia mutations in Asians and American blacks. Hum Mutat 1994;3:59–63.
Huisman THJ, Carver MFH, Baysal E: A syllabus of thalassemia mutations. Augusta, The Sickle Cell Anemia Foundation; 1997.
Ng ISL, Ong JBK, Tan CL, Law HY: Beta-thalassemia mutations in Singapore – A strategy for prenatal diagnosis. Hum Genet 1994;94:385–388.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.