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

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.