Table XXI

TABLE XXI.

The Nondeletional Alpha-Thalassemia Alleles

Mechanism Sequence Mutation

(Hyper)Unstable Hbs; Shortened Alpha Chains

alpha2 point mutation alpha29 CTG->CCG; Leu->Pro

point mutation alpha104 TGC->TAC; Cys->Tyr

point mutation alpha109 CTG->CGG; Leu->Arg

frameshift (-12 nts) alpha112-116 deleted: C·CTC·CCC·GCC·GA

point mutation alpha116 GAG->TAG; Glu->Term

point mutation alpha125 CTG->CCG; Leu->Pro

point mutation alpha129 CTG->CCG; Leu->Pro

point mutation alpha130 GCT->CCT; Ala->Pro

point mutation alpha131 TCT->CCT; Ser->Pro

alpha1 frameshift (-3 nts) alpha38-39 deleted: ACC; -Thr

frameshift (-13 nts) alpha51-55 deleted: GC·TCT·GCC·CAG·GT

point mutation alpha59 GGC->GAC; Gly->Asp

alpha2 or alpha1 point mutation alpha110 GCC->GAC; Ala->Asp

-alpha(3.7) point mutation alpha14 TGG->AGG; Trp->Arg

mRNA Translation; Initiation Codon

alpha2 point mutation alpha0 ATG->ACG

frameshift (-1 nt) alpha0 ATG->A-G

alpha1 point mutation alpha0 ATG->GTG

-alpha(3.7) point mutation alpha0 ATG->GTG

frameshift (-2 nts) alpha0 CCACCATGG->CC- -CATGG

mRNA Translation; Terminating Codon

alpha2 point mutation alpha142 TAA->CAA (Gln) Hb Constant Spring

point mutation alpha142 TAA->TCA (Ser) Hb Koya Dora

point mutation alpha142 TAA->AAA (Lys) Hb Icaria

point mutation alpha142 TAA->GAA (Glu) Hb Seal Rock

point mutation alpha142 TAA->TAT (Tyr) Hb Paksé

mRNA Translation; Others

alpha2 point mutation IVS-I-116 A->G

alpha1 point mutation IVS-I-117 G->A

-alpha(3.7) frameshift (-2 nts) codons 30/31 GAG·AGG->GAG·- -G [the hybrid -alpha(3.7) is nonfunctional; an alpha-thal-1 condition is the final result]

mRNA Processing

alpha2 deletion (-5 nts) IVS-I donor site deletion: GAG^GTGAGG->GAGG- - - - -

alpha2 point mutation poly A site AATAAA->AATAAG

point mutation poly A site AATAAA->AATGAA

deletion (-2 nts) poly A site AATAAA->AATA- -

deletion (-16 nts) poly A site and 3'UTR cccttcctggtctttgAATAAA->c-ATAAA

	Mechanism	Sequence	Mutation
(Hyper)Unstable Hbs; Shortened Alpha Chains
alpha2	point mutation	alpha29	CTG->CCG; Leu->Pro
	point mutation	alpha104	TGC->TAC; Cys->Tyr
	point mutation	alpha109	CTG->CGG; Leu->Arg
	frameshift (-12 nts)	alpha112-116	deleted: C·CTC·CCC·GCC·GA
	point mutation	alpha116	GAG->TAG; Glu->Term
	point mutation	alpha125	CTG->CCG; Leu->Pro
	point mutation	alpha129	CTG->CCG; Leu->Pro
	point mutation	alpha130	GCT->CCT; Ala->Pro
	point mutation	alpha131	TCT->CCT; Ser->Pro
alpha1	frameshift (-3 nts)	alpha38-39	deleted: ACC; -Thr
	frameshift (-13 nts)	alpha51-55	deleted: GC·TCT·GCC·CAG·GT
	point mutation	alpha59	GGC->GAC; Gly->Asp
alpha2 or alpha1	point mutation	alpha110	GCC->GAC; Ala->Asp
-alpha(3.7)	point mutation	alpha14	TGG->AGG; Trp->Arg
mRNA Translation; Initiation Codon
alpha2	point mutation	alpha0	ATG->ACG
	frameshift (-1 nt)	alpha0	ATG->A-G
alpha1	point mutation	alpha0	ATG->GTG
-alpha(3.7)	point mutation	alpha0	ATG->GTG
	frameshift (-2 nts)	alpha0	CCACCATGG->CC- -CATGG
mRNA Translation; Terminating Codon
alpha2	point mutation	alpha142	TAA->CAA (Gln) Hb Constant Spring
	point mutation	alpha142	TAA->TCA (Ser) Hb Koya Dora
	point mutation	alpha142	TAA->AAA (Lys) Hb Icaria
	point mutation	alpha142	TAA->GAA (Glu) Hb Seal Rock
	point mutation	alpha142	TAA->TAT (Tyr) Hb Paksé
mRNA Translation; Others
alpha2	point mutation	IVS-I-116	A->G
alpha1	point mutation	IVS-I-117	G->A
-alpha(3.7)	frameshift (-2 nts)	codons 30/31	GAG·AGG->GAG·- -G [the hybrid -alpha(3.7) is nonfunctional; an alpha-thal-1 condition is the final result]
mRNA Processing
alpha2	deletion (-5 nts)	IVS-I donor site	deletion: GAG^GTGAGG->GAGG- - - - -
alpha2	point mutation	poly A site	AATAAA->AATAAG
	point mutation	poly A site	AATAAA->AATGAA
	deletion (-2 nts)	poly A site	AATAAA->AATA- -
	deletion (-16 nts)	poly A site and 3'UTR	cccttcctggtctttgAATAAA->c-ATAAA

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.