MUTATION		5'UTR; +22 (G->A)
AMINO ACID REPLACEMENT		None
TYPE OF BETA-THAL		beta+
MECHANISM		Decreased transcription; decreased binding of ribosomes (see below)
IDENTIFICATION		Amplification of the beta-globin gene; DNA sequencing; dot-blot analysis with allele specific probes (ASO)
HEMATOLOGY IN HETEROZYGOTE(S)		# alpha Hb MCV MCH Hb A2 Hb F 4 12.5 75.0 23.4 4.4 0.7 4 15.0 84.5 25.2 3.3 0.4 4 12.4 75.0 21.3 4.0 2.9 - 14.4 80.0 24.3 3.9 0.6
HEMATOLOGY IN HOMOZYGOTE(S)		Not reported
OCCURRENCE		Found in families from Turkey and one from Bulgaria; in an Italian family
HAPLOTYPE		[- - + + - + -]
FOUND IN COMBINATION WITH ABNORMAL HB(S)		Not reported
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S)		With different beta-thal alleles as follows:
		Sex-Age Genotype # alpha Hb PCV MCV MCH Hb A2 Hb F M-10 FSC-8/+22 4 5.5 .175 76.0 23.8 4.0 5.7 M-7 FSC-8/+22 4 6.4 .220 82.0 23.8 3.0 8.6 M-7 IVS-I-110/+22 - 10.0 .389 80.0 23.6 2.8 25.8 F-3 IVS-II-1/+22 - 10.5 .321 80.0 26.3 4.5 15.0 F-2 IVS-II-1/+22 - 10.5 .336 80.0 25.0 4.0 14.0
OTHER INFORMATION		Another possibility: the mutation creates an ATG initiation codon which when utilized would result in the premature termination 36 bp 3' downstream (Ref. 2)

REFERENCES
1.		Öner, R., Agarwal, S., Dimovski, A.J., Efremov, G.D., Petkov, G.H., Altay, Ç., Gurgey, A., and Huisman, T.H.J.: Hemoglobin, 15:67, 1991.
2.		Cai, S-P., Eng, B., Francombe, W.H., Olivieri, N.F., Kendall, A.G., Waye, J.S., and Chui, D.H.K.: Blood, 79:1342, 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.