MUTATION		G->T at codon 116 of the alpha2 gene; GAG->TAG
AMINO ACID REPLACEMENT		Stop codon at codon 116; no abnormal protein observed
TYPE OF ALPHA-THAL		alpha-Thal-2 [alpha(T)alpha/alphaalpha]
MECHANISM		The absence of a protein product results in a deficit in alpha chain production
IDENTIFICATION		Cloning of the alpha2-globin gene; sequencing
HEMATOLOGY IN HETEROZYGOTE(S)		One heterozygote was found: Hb 11.6 g/dl; MCV 88 fl; MCH 30 pg; alpha/beta ratio 0.77
HEMATOLOGY IN HOMOZYGOTE(S)		Not observed
OCCURRENCE		In a Black family
HAPLOTYPE		Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S)		Not reported
FOUND IN COMBINATION		With an alpha-thal-2 [-alpha(3.7)] in four members with the phenotype of a moderately severe alpha-thal; Hb 10.0-13.7 g/dl; MCV 66-72 fl; MCH 21.7-23.7 pg; alpha/beta ratio 0.75-0.86
OTHER INFORMATION		None

REFERENCES
1.		Liebhaber, S.A., Coleman, M.B., Adams, J.G., III, Fash, F.E., and Steinberg, M.H.: J. Clin. Invest., 80: 154, 1987.

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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.