MUTATION		Codon 19 (A->G); AAC(Asn)->AGC(Ser)
AMINO ACID REPLACEMENT		Asn->Ser (Hb Malay)
TYPE OF BETA-THAL		beta+
MECHANISM		This change of one nucleotide creates an alternate splicing site between codons 17 and 18, decreasing the efficiency of the normal donor site at IVS-I to ~60%
IDENTIFICATION		Amplification of the beta-globin gene; DNA sequencing; dot-blot analysis with allele specific probes; ASO
HEMATOLOGY IN HETEROZYGOTE(S)		Hb 12-16 g/dl; MCV 67-79 fl; MCH 22.5-25.5 pg; Hb A2 3.4-3.8%; Hb F <1%
HEMATOLOGY IN HOMOZYGOTE(S)		Hb 8.6-9.1 g/dl; MCV 51-59 fl; MCH 17-19 pg; Hb A2 5-7%; Hb F 10-25%; thalassemia intermedia
OCCURRENCE		Found in Malaysian families
HAPLOTYPE		New [- + + - + + + -]
FOUND IN COMBINATION WITH ABNORMAL HB(S)		With Hb E; Hb 9.8-10.2 g/dl; MCV 58-64 fl; MCH 19.5-20.0 pg; Hb A2 n.d.; Hb F 4-10%; thalassemia intermedia; can easily be misdiagnosed as a Hb E heterozygote, although Hb E = ~55% and Hb Malay (with an electrophoretic mobility like Hb A) = ~45%
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S)		Not reported
OTHER INFORMATION		None

REFERENCES
1.		Yang, K.G., Kutlar, F., George, E., Wilson, J.B., Kutlar, A., Stoming, T.A., Gonzalez-Redondo, J.M., and Huisman, T.H.J.: Br. J. Haematol., 72:73, 1989.
2.		Thein, S.L., Winichagoon, P., Hesketh, C., Best, S., Fucharoen, S., Wasi, P., and Weatherall, D.J.: Am. J. Hum. Genet., 47:369, 1990.

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This material is from the book A Syllabus of Thalassemia Mutations (1997) by Titus H.J. Huisman, Marianne F.H. Carver, and Erol Baysal, published by The Sickle Cell Anemia Foundation in Augusta, GA, USA. Copyright © 1997 by Titus H.J. Huisman. All rights reserved. Neither this work nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, microfilming and recording, or by any information storage and retrieval systems, without permission in writing from the Author.