Codon.114.(-CT,.+G),.CTG(Leu)-@-GG.html

MUTATION

Codon 114 (-CT; +G); CTG(Leu)->-GG

AMINO ACID REPLACEMENT

Extended beta chain (Hb Geneva)

TYPE OF BETA-THAL

beta° (dominant beta-thal trait)

MECHANISM

This frameshift results in the synthesis of an extended beta chain of 156 amino acids; a new stop codon at codon 157 (TAA)

IDENTIFICATION

Amplification of the beta-globin gene; sequencing of amplified DNA; ApaI digestion because a new restriction site is formed

HEMATOLOGY IN HETEROZYGOTE(S)

Some patients were splenectomized

Sex-Age	F-44	M-38	M-22	F-22
Hb (g/dl)	9.5	11.6	10.6	10.5
MCV (fl)	81.0	77.0	70.0	68.0
MCH (pg)	26.8	26.0	22.0	21.0
Reticulocytes (%)	36.0	42.5	4.6	5.8
Morphology	Abnormal	Abnormal	Abnormal	Abnormal
Heinz bodies	+++	+++	+++	+++
Hb A₂ (%)	3.6	n.d.	4.0	3.3
Hb F (%)	2.4	1.6	3.6	1.6
^Ggamma in Hb F (%)	26.3	25.1	55.4	21.4

HEMATOLOGY IN HOMOZYGOTE(S)

Not observed

OCCURRENCE

In a large Swiss family

HAPLOTYPE

Not determined

FOUND IN COMBINATION WITH ABNORMAL HB(S)

Not reported

FOUND IN COMBINATION WITH BETA-THAL ALLELE(S)

Not reported

OTHER INFORMATION

Attempts to isolate the beta^X chain (or Hb X) were not successful; inclusion bodies contained mainly alpha chains


REFERENCES
1.		Beris, Ph., Miescher, P.A., Diaz-Chico, J.C., Han, I-S., Kutlar, A., Hu, H., Wilson, J.B., and Huisman, T.H.J.: Blood, 72:801, 1988.

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.