MUTATION		Codon 15 (G->A); TGG(Trp)->TGA(stop codon)
AMINO ACID REPLACEMENT		None
TYPE OF BETA-THAL		beta°
MECHANISM		This change of one nucleotide results in termination of translation at codon 15
IDENTIFICATION		Sequencing of amplified DNA and hybridization with allele specific oligonucleotide probes; ASO
HEMATOLOGY IN HETEROZYGOTE(S)		Hb 11.9 g/dl; MCV 66.5 fl; MCH 21 pg; Hb A2 5.1%; Hb F 1.3% (n=11)
HEMATOLOGY IN HOMOZYGOTE(S)		Two homozygotes had severe, transfusion-dependent anemia
OCCURRENCE		Several Portuguese families; found in 15-16% of the beta-thal heterozygotes detected in Central Portugal; a Black family from the Southeastern USA; see Table VII
HAPLOTYPE		Not reported
FOUND IN COMBINATION WITH ABNORMAL HB(S)		With Hb S; this condition is characterized by a moderate anemia and sickling; with Hb Shelby [beta131(H9) Gln->Lys] it causes a milder anemia (Hb 10-11 g/dl; MCV 60 fl; MCH 19 pg; Hb A2 7.0%; Hb F 5.7%)
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S)		Not reported
OTHER INFORMATION		Mutation is linked to the C->T polymorphism at codon 2

REFERENCES
1.		Ribeiro, M.L.S., Baysal, E., Kutlar, A., Tamagnini, G.P., Gonçalves, P., Lopes, D., and Huisman, T.H.J.: Br. J. Haematol., 80:567, 1992.
2.		Cürük, M.A., Kutlar, A., and Huisman, T.H.J.: Hemoglobin, 16:417, 1992.

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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.