T-@C.at.codon.131.of.the.alpha2.gene,.TC.html


MUTATION		T->C at codon 131 of the alpha2 gene; TCT->CCT

AMINO ACID REPLACEMENT		Ser->Pro replacement at position 131 (Hb Questembert)
TYPE OF ALPHA-THAL		alpha-Thal-2 [alpha(T)alpha/alphaalpha]
MECHANISM		Unstable Hb leads to a deficit in alpha chain production
IDENTIFICATION		Gene mapping; amplification of the alpha2-globin gene; sequencing
HEMATOLOGY IN HETEROZYGOTE(S)		Hb 10.0-10.3 g/dl; MCV 73-75 fl; MCH 24-26 pg; reticulocytes 115-300 x 10⁹/l; alpha/beta ratio 0.80-0.82
HEMATOLOGY IN HOMOZYGOTE(S)		Not observed
OCCURRENCE		In a French family of Yugoslavian descent (two carriers)
HAPLOTYPE		Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S)		Not reported
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S)		Not reported
OTHER INFORMATION		Heat stability test was positive; the abnormal Hb was detectable by electrophoresis at pH 8.6; by chromatography; quantity ~11%


REFERENCES
1.		Rochette, J., Barnetson, R., Thein, S.L., Varet, B., and Valensi, F.: Am. J. Hematol., 48:289, 1995.

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.