scholarly journals A novel beta-thalassemia frameshift mutation (codon 14/15), detectable by direct visualization of abnormal restriction fragment in amplified genomic DNA

Blood ◽  
1988 ◽  
Vol 72 (4) ◽  
pp. 1420-1423
Author(s):  
V Chan ◽  
TK Chan ◽  
YW Kan ◽  
D Todd

A new frameshift mutation due to an insertion of G between codon 14/15 of the beta-globin gene was found in two unrelated Chinese patients with Cooley's anemia. The first patient (W.S.) was homozygous for haplotype 5 (Chinese) and carried a codon 41/42 (four base pair deletion) mutant, while the second patient (C.K.) was homozygous for haplotype 2 (Chinese), and also had a codon 17 (A----T) nonsense mutation. Molecular cloning and M13 sequencing of the beta gene in patient W.S. revealed that the new mutant was found in a beta-globin gene framework type 3 (Asian). Direct sequencing was performed on polymerase chain reaction-amplified genomic DNA from patient C.K. With the new mutation, an additional BstNI or EcoRII recognition site is generated and the abnormal restriction fragment (134 basepair) can be directly visualized on polyacrylamide gel electrophoresis of the amplified genomic DNA.

Blood ◽  
1988 ◽  
Vol 72 (4) ◽  
pp. 1420-1423 ◽  
Author(s):  
V Chan ◽  
TK Chan ◽  
YW Kan ◽  
D Todd

Abstract A new frameshift mutation due to an insertion of G between codon 14/15 of the beta-globin gene was found in two unrelated Chinese patients with Cooley's anemia. The first patient (W.S.) was homozygous for haplotype 5 (Chinese) and carried a codon 41/42 (four base pair deletion) mutant, while the second patient (C.K.) was homozygous for haplotype 2 (Chinese), and also had a codon 17 (A----T) nonsense mutation. Molecular cloning and M13 sequencing of the beta gene in patient W.S. revealed that the new mutant was found in a beta-globin gene framework type 3 (Asian). Direct sequencing was performed on polymerase chain reaction-amplified genomic DNA from patient C.K. With the new mutation, an additional BstNI or EcoRII recognition site is generated and the abnormal restriction fragment (134 basepair) can be directly visualized on polyacrylamide gel electrophoresis of the amplified genomic DNA.


Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 583-586 ◽  
Author(s):  
JC Diaz-Chico ◽  
KG Yang ◽  
A Kutlar ◽  
AL Reese ◽  
M Aksoy ◽  
...  

Abstract Detailed gene mapping analyses of genomic DNA from two Turkish subjects with a beta-thalassemia trait demonstrated an approximately 300 bp deletion, which is located between the Rsa I restriction site 128 bp 5′ to the Cap site and the Acc I restriction site 284 bp 3′ to the same Cap site; it includes the 5′ beta promoter region, the first exon, and (part of) the IVS-I. Heterozygotes for this and two other beta- thalassemia types, which are also caused by deletions involving 5′ beta promoter sequences, appear to have higher hemoglobin (Hb) A2 levels, perhaps because the loss of this promoter results in an increased transcription of the delta globin gene, as delta and beta promoters may be influenced by the same enhancing sequences 3′ to the beta globin gene.


Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 823-827 ◽  
Author(s):  
R Galanello ◽  
E Dessi ◽  
MA Melis ◽  
M Addis ◽  
MA Sanna ◽  
...  

Abstract In this study we have carried out alpha- and beta-globin gene analysis and defined the beta-globin gene polymorphisms in a group of patients with thalassemia intermedia of Sardinian descent. A group of patients (109) with thalassemia major of the same origin served as control. Characterization of the beta-thalassemia mutation showed either a frameshift mutation at codon 6 or a codon 39 nonsense mutation. We found that homozygotes for the frameshift mutation at codon 6 or compound heterozygotes for this mutation and for the codon 39 nonsense mutation develop thalassemia intermedia more frequently than thalassemia major. The frameshift mutation at codon 6 was associated with haplotype IX that contains the C-T change at position -158 5′ to the G gamma globin gene implicated in high gamma chain production and thus the mild phenotype. In patients' homozygotes for codon 39 nonsense mutation, those with thalassemia intermedia more frequently had the two- gene deletion form of alpha-thalassemia, or functional loss of the alpha 2 gene as compared with those with thalassemia major. In a few siblings with thalassemia major and intermedia, the thalassemia intermedia syndrome correlated with the presence of the -alpha/-alpha genotype. No cause for the mild phenotype was detected in the majority of patients who had not inherited either haplotype IX or alpha- thalassemia.


2008 ◽  
Vol 119 (1) ◽  
pp. 28-37 ◽  
Author(s):  
Giordana Feriotto ◽  
Francesca Salvatori ◽  
Alessia Finotti ◽  
Giulia Breveglieri ◽  
Marina Venturi ◽  
...  

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 583-586
Author(s):  
JC Diaz-Chico ◽  
KG Yang ◽  
A Kutlar ◽  
AL Reese ◽  
M Aksoy ◽  
...  

Detailed gene mapping analyses of genomic DNA from two Turkish subjects with a beta-thalassemia trait demonstrated an approximately 300 bp deletion, which is located between the Rsa I restriction site 128 bp 5′ to the Cap site and the Acc I restriction site 284 bp 3′ to the same Cap site; it includes the 5′ beta promoter region, the first exon, and (part of) the IVS-I. Heterozygotes for this and two other beta- thalassemia types, which are also caused by deletions involving 5′ beta promoter sequences, appear to have higher hemoglobin (Hb) A2 levels, perhaps because the loss of this promoter results in an increased transcription of the delta globin gene, as delta and beta promoters may be influenced by the same enhancing sequences 3′ to the beta globin gene.


Blood ◽  
1989 ◽  
Vol 73 (6) ◽  
pp. 1695-1698 ◽  
Author(s):  
R Spiegelberg ◽  
C Aulehla-Scholz ◽  
H Erlich ◽  
J Horst

Abstract The base composition around a recently detected deletion in the human beta-globin gene was determined by direct DNA sequencing of an enzymatically amplified DNA segment. The deletion removes 290 base pairs (bp), including the entire exon 1 and the mRNA cap site. In the vicinity of the deletion endpoints, the normal beta-globin gene contains direct and inverted repeats which may have taken part in generation of this deletion.


Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 823-827 ◽  
Author(s):  
R Galanello ◽  
E Dessi ◽  
MA Melis ◽  
M Addis ◽  
MA Sanna ◽  
...  

In this study we have carried out alpha- and beta-globin gene analysis and defined the beta-globin gene polymorphisms in a group of patients with thalassemia intermedia of Sardinian descent. A group of patients (109) with thalassemia major of the same origin served as control. Characterization of the beta-thalassemia mutation showed either a frameshift mutation at codon 6 or a codon 39 nonsense mutation. We found that homozygotes for the frameshift mutation at codon 6 or compound heterozygotes for this mutation and for the codon 39 nonsense mutation develop thalassemia intermedia more frequently than thalassemia major. The frameshift mutation at codon 6 was associated with haplotype IX that contains the C-T change at position -158 5′ to the G gamma globin gene implicated in high gamma chain production and thus the mild phenotype. In patients' homozygotes for codon 39 nonsense mutation, those with thalassemia intermedia more frequently had the two- gene deletion form of alpha-thalassemia, or functional loss of the alpha 2 gene as compared with those with thalassemia major. In a few siblings with thalassemia major and intermedia, the thalassemia intermedia syndrome correlated with the presence of the -alpha/-alpha genotype. No cause for the mild phenotype was detected in the majority of patients who had not inherited either haplotype IX or alpha- thalassemia.


Blood ◽  
1989 ◽  
Vol 73 (6) ◽  
pp. 1695-1698
Author(s):  
R Spiegelberg ◽  
C Aulehla-Scholz ◽  
H Erlich ◽  
J Horst

The base composition around a recently detected deletion in the human beta-globin gene was determined by direct DNA sequencing of an enzymatically amplified DNA segment. The deletion removes 290 base pairs (bp), including the entire exon 1 and the mRNA cap site. In the vicinity of the deletion endpoints, the normal beta-globin gene contains direct and inverted repeats which may have taken part in generation of this deletion.


Blood ◽  
1988 ◽  
Vol 71 (3) ◽  
pp. 766-770
Author(s):  
PT Curtin ◽  
YW Kan

We have previously described an English family with gamma delta beta- thalassemia in which a large deletion stops 25 kilobases (kb) upstream from the beta-globin gene locus, and yet the beta-globin gene is inactive in vivo. Affected family members had a beta-thalassemia minor phenotype with a normal hemoglobin A2 level. Gene mapping showed that these subjects were heterozygous for a chromosome bearing a large deletion that began in the G gamma-globin gene, extended through the epsilon-globin gene, and continued upstream for at least 75 kb. The A gamma-, delta-, and beta-globin gene loci on this chromosome were intact. To examine the possibility that an additional defect was present in the beta-globin gene, we cloned, sequenced, and examined the expression of the beta-globin gene from the affected chromosome. No mutation was found in the beta-globin gene sequence from 990 base-pairs 5′ to the cap site to 350 basepairs 3′ to the polyadenylation signal. The gene was subcloned into an expression vector and introduced into HeLa cells. Analysis of RNA derived from these cells, using a ribonuclease protection assay, revealed qualitatively and quantitatively normal transcription. Thus a structurally and functionally normal beta-globin gene is inactive in the presence of a large deletion more than 25 kb upstream. The loss of beta-globin gene function may be due to disturbance of chromatin conformation caused by the deletion or may be the result of loss of upstream sequences that are necessary for beta-globin gene expression in vivo.


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