MUTATION Initiation codon (A->G); ATG->GTG of an alpha2alpha1 hybrid gene -alpha(-3.7 kb)
 
AMINO ACID REPLACEMENT None
TYPE OF ALPHA-THAL alpha-Thal-1 [-alpha(T)/alphaalpha]
MECHANISM The mutation is found in the initiation codon of an alpha2alpha1 hybrid gene [-alpha(T)] resulting in an alpha-thal-1-like condition; the alpha2alpha1 gene is of the -alpha(3.7 kb) deletion type
IDENTIFICATION Gene mapping; cloning; sequencing
HEMATOLOGY IN HETEROZYGOTE(S) Father and daughter [-alpha(T)/alphaalpha]: Hb 14.6, 11.9 g/dl; MCV 71, 67 fl; alpha/(beta+gamma) ratio 0.87, 0.87; Hb A2 1.6, 1.6%. Mother [-alpha(-3.7)/alphaalpha]: Hb 15.0 g/dl; MCV 81 fl; alpha/(beta+gamma) ratio 0.92; Hb A2 1.5%
HEMATOLOGY IN HOMOZYGOTE(S) Not observed
OCCURRENCE In a Black family from Canada
HAPLOTYPE Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S) Not reported
FOUND IN COMBINATION With an -alpha(3.7 kb) deletion: [-alpha(T)/-alpha(-3.7)]; two subjects with Hb H disease; Hb 9.4, 9.9 g/dl; MCV 51, 54 fl; alpha/(beta+gamma) ratio 0.41, 0.43; Hb A2 1.0, 0.4%; Hb H 2.4, 7.2%; Hb Bart's 2.1, 1.4%
OTHER INFORMATION None
       
REFERENCES
1. Olivieri, N.F., Chang, L.S., Poon, A.O., Michelson, A.M., and Orkin, S.H.: Blood, 70:729, 1987.


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.