scholarly journals Clinical and genetic heterogeneity in black patients with homozygous beta-thalassemia from the southeastern United States

Blood ◽  
1988 ◽  
Vol 72 (3) ◽  
pp. 1007-1014 ◽  
Author(s):  
JM Gonzalez-Redondo ◽  
TA Stoming ◽  
KD Lanclos ◽  
YC Gu ◽  
A Kutlar ◽  
...  
Keyword(s):  
South Carolina ◽  
Genomic Dna ◽  
Stop Codon ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Nucleotide Substitutions ◽  
Taq Polymerase ◽  
Black Patients ◽  
Codon 61

Abstract The presence of various substitutions and deletions resulting in beta- thalassemia was studied in 19 black patients with homozygous beta- thalassemia and in numerous relatives; all patients were from Georgia, South Carolina, and Alabama. Methodology included gene mapping, amplification of genomic DNA with Taq polymerase, identification of known nucleotide substitutions or a single nucleotide deletion through hybridization with synthetic oligonucleotides, cloning and sequencing of a beta-globin gene, and sequencing of amplified genomic DNA. Of the 38 chromosomes tested, 21 (55%) had the A----G substitution at nt -29, eight (21%) had the C----T substitution at nt -88, three (8%) had the substitution at codon 24, while one each of the following abnormalities were also detected: frameshift at codon 6, a C----A mutation at nt 848 of the beta IVS-II (new), an A----T mutation at codon 61 (new), a deletion of 1.35 kilobases including the 5′ end of beta, a Ggamma(Agammadelta beta) degree-thalassemia, and one thalassemia determinant that remained unidentified. The C----A mutation at nt 848 of IVS-II occurred at a position 3 nucleotides 5′ to the third exon, adjacent to the invariant AG dinucleotide of the acceptor sequence. The A----T mutation in codon 61 (AAG----TAG) resulted in the creation of a stop codon and thus in beta degree-thalassemia. The various mutations occurred on chromosomes with different haplotypes; however, chromosomes with a specific mutation but with different haplotypes belonged to one specific framework, which suggested that crossovers were responsible for these different types. Hemoglobin (Hb) F levels were generally high (55% to 75% with 98.5% in one patient with beta degree/beta degree); a few patients with specific haplotypes and an alpha-thalassemia-2 heterozygosity had a lower Hb F level. The Ggamma in the Hb F was consistently high when the C----T mutation occurred at nt -158 to the Cap site of the Ggamma-globin gene; seven patients with +/+ at this site had an average Ggamma of 73.8%, eight patients with +/- had 64.8%, and one patient with -/- had 34.2%. Variations in hematologic values and in Hb F, Ggamma, and Hb A2 levels of relatives with a beta- thalassemia heterozygosity depended to some extent on the types of mutations or deletions and on the haplotypes of the chromosomes with the beta-thalassemia determinant.

scholarly journals Clinical and genetic heterogeneity in black patients with homozygous beta-thalassemia from the southeastern United States

Blood ◽  
1988 ◽  
Vol 72 (3) ◽  
pp. 1007-1014 ◽  
Author(s):  
JM Gonzalez-Redondo ◽  
TA Stoming ◽  
KD Lanclos ◽  
YC Gu ◽  
A Kutlar ◽  
...  
Keyword(s):  
South Carolina ◽  
Genomic Dna ◽  
Stop Codon ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Nucleotide Substitutions ◽  
Taq Polymerase ◽  
Black Patients ◽  
Codon 61

The presence of various substitutions and deletions resulting in beta- thalassemia was studied in 19 black patients with homozygous beta- thalassemia and in numerous relatives; all patients were from Georgia, South Carolina, and Alabama. Methodology included gene mapping, amplification of genomic DNA with Taq polymerase, identification of known nucleotide substitutions or a single nucleotide deletion through hybridization with synthetic oligonucleotides, cloning and sequencing of a beta-globin gene, and sequencing of amplified genomic DNA. Of the 38 chromosomes tested, 21 (55%) had the A----G substitution at nt -29, eight (21%) had the C----T substitution at nt -88, three (8%) had the substitution at codon 24, while one each of the following abnormalities were also detected: frameshift at codon 6, a C----A mutation at nt 848 of the beta IVS-II (new), an A----T mutation at codon 61 (new), a deletion of 1.35 kilobases including the 5′ end of beta, a Ggamma(Agammadelta beta) degree-thalassemia, and one thalassemia determinant that remained unidentified. The C----A mutation at nt 848 of IVS-II occurred at a position 3 nucleotides 5′ to the third exon, adjacent to the invariant AG dinucleotide of the acceptor sequence. The A----T mutation in codon 61 (AAG----TAG) resulted in the creation of a stop codon and thus in beta degree-thalassemia. The various mutations occurred on chromosomes with different haplotypes; however, chromosomes with a specific mutation but with different haplotypes belonged to one specific framework, which suggested that crossovers were responsible for these different types. Hemoglobin (Hb) F levels were generally high (55% to 75% with 98.5% in one patient with beta degree/beta degree); a few patients with specific haplotypes and an alpha-thalassemia-2 heterozygosity had a lower Hb F level. The Ggamma in the Hb F was consistently high when the C----T mutation occurred at nt -158 to the Cap site of the Ggamma-globin gene; seven patients with +/+ at this site had an average Ggamma of 73.8%, eight patients with +/- had 64.8%, and one patient with -/- had 34.2%. Variations in hematologic values and in Hb F, Ggamma, and Hb A2 levels of relatives with a beta- thalassemia heterozygosity depended to some extent on the types of mutations or deletions and on the haplotypes of the chromosomes with the beta-thalassemia determinant.

scholarly journals An approximately 300 bp deletion involving part of the 5' beta-globin gene region is observed in members of a Turkish family with beta- thalassemia

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 583-586 ◽  
Author(s):  
JC Diaz-Chico ◽  
KG Yang ◽  
A Kutlar ◽  
AL Reese ◽  
M Aksoy ◽  
...  
Keyword(s):  
Promoter Region ◽  
Genomic Dna ◽  
Restriction Site ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Promoter Sequences ◽  
Beta Globin Gene ◽  
Turkish Family ◽  
Thalassemia Trait

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.

scholarly journals Use of oligonucleotide hybridization in the characterization of a beta zero-thalassemia gene (beta 37 TGG----TGA) in a Saudi Arabian family [published erratum appears in Blood 1986 Jul;68(1):323]

Blood ◽  
1986 ◽  
Vol 67 (4) ◽  
pp. 1185-1188
Author(s):  
CD Boehm ◽  
CE Dowling ◽  
PG Waber ◽  
PJ Giardina ◽  
HH Jr Kazazian
Keyword(s):  
Genomic Dna ◽  
Globin Gene ◽  
Point Mutations ◽  
Saudi Arabian ◽  
Globin Genes ◽  
Beta Globin ◽  
Nucleotide Substitutions ◽  
Exon 2 ◽  
Oligonucleotide Hybridization

Analysis of restriction site polymorphisms in the beta-globin gene cluster of a Saudi Arabian female with beta zero-thalassemia demonstrated that both of her beta-globin genes were missing a nonpolymorphic AvaII site in exon 2. Examination of the normal nucleotide sequence surrounding this AvaII site revealed that either of two nucleotide substitutions, TGG----TAG or TGG----TGA, could produce a nonsense codon at codon 37 and eliminate the AvaII site. Consequently, two oligonucleotides (19-mers spanning codons 36 through 41 and containing either TAG or TGA at codon 37) were synthesized and hybridized against genomic DNA of the proband and her family. Specific hybridization with one of the oligomers demonstrated that the patient's beta o-thalassemia was the result of homozygosity for the TGG----TGA mutation at codon 37. In certain cases, oligonucleotide hybridization using genomic DNA may obviate the need for gene cloning and sequencing in the characterization of point mutations.

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
Keyword(s):  
Restriction Fragment ◽  
Genomic Dna ◽  
Frameshift Mutation ◽  
Globin Gene ◽  
Polyacrylamide Gel Electrophoresis ◽  
Chinese Patients ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Beta Globin Gene ◽  
Base Pair Deletion

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.

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
Keyword(s):  
Restriction Fragment ◽  
Genomic Dna ◽  
Frameshift Mutation ◽  
Globin Gene ◽  
Polyacrylamide Gel Electrophoresis ◽  
Chinese Patients ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Beta Globin Gene ◽  
Base Pair Deletion

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.

scholarly journals Beta-thalassemia due to two novel nucleotide substitutions in consensus acceptor splice sequences of the beta-globin gene

Blood ◽  
1989 ◽  
Vol 73 (4) ◽  
pp. 914-918
Author(s):  
C Wong ◽  
SE Antonarakis ◽  
SC Goff ◽  
SH Orkin ◽  
BG Forget ◽  
...  
Keyword(s):  
Splice Site ◽  
Rna Splicing ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Nucleotide Substitutions ◽  
Splice Site Selection ◽  
Exon 2 ◽  
Consensus Sequences ◽  
Beta Globin Gene

We have identified two novel RNA-splicing mutations affecting a critical nucleotide (nt) in the acceptor consensus sequences at both the IVS-1/exon 2 and IVS-2/exon 3 junctions of the human beta-globin gene. Both mutations are single nt substitutions, T to G and C to A, at position -3 adjacent to the invariant AG dinucleotide. For the IVS- 2/exon 3 mutation abnormal splicing into the cryptic splice site at IVS- 2 nt 579 is documented. Identification of these two mutations provides further support for the importance of the location of specific nucleotides within the consensus sequences in splice site selection and RNA processing.

scholarly journals Beta-thalassemia due to two novel nucleotide substitutions in consensus acceptor splice sequences of the beta-globin gene

Blood ◽  
1989 ◽  
Vol 73 (4) ◽  
pp. 914-918 ◽  
Author(s):  
C Wong ◽  
SE Antonarakis ◽  
SC Goff ◽  
SH Orkin ◽  
BG Forget ◽  
...  
Keyword(s):  
Splice Site ◽  
Rna Splicing ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Nucleotide Substitutions ◽  
Splice Site Selection ◽  
Exon 2 ◽  
Consensus Sequences ◽  
Beta Globin Gene

Abstract We have identified two novel RNA-splicing mutations affecting a critical nucleotide (nt) in the acceptor consensus sequences at both the IVS-1/exon 2 and IVS-2/exon 3 junctions of the human beta-globin gene. Both mutations are single nt substitutions, T to G and C to A, at position -3 adjacent to the invariant AG dinucleotide. For the IVS- 2/exon 3 mutation abnormal splicing into the cryptic splice site at IVS- 2 nt 579 is documented. Identification of these two mutations provides further support for the importance of the location of specific nucleotides within the consensus sequences in splice site selection and RNA processing.

scholarly journals Molecular characterization of a high A2 beta thalassemia by direct sequencing of single strand enriched amplified genomic DNA

Blood ◽  
1989 ◽  
Vol 73 (4) ◽  
pp. 924-930
Author(s):  
SL Thein ◽  
C Hesketh ◽  
JM Brown ◽  
AV Anstey ◽  
DJ Weatherall
Keyword(s):  
Genomic Dna ◽  
Direct Sequencing ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Heterozygous State ◽  
Beta Globin ◽  
Anglo Saxon ◽  
Base Pairs ◽  
High Level ◽  
Endonuclease Mapping

Two families, one of Anglo-Saxon-Dutch descent, and the other, West Indian black, have an atypical beta thalassemia characterized by an unusually high level of Hb A2 in the heterozygous state. Restriction endonuclease mapping showed a deletion of about 1.35 kilobase (kb) in the 5′ region of the beta globin gene. Direct sequencing of a specific region of genomic DNA amplified by a new modification of the polymerase chain reaction defined the deletion to be 1,393 base pairs (bp) and to be the same in both families. The deletion extends from 485 bp 5′ to the mRNA CAP site to the middle of the second intervening sequence. This deletion, together with three others previously described that remove the 5′ end of the beta gene but leave the delta gene intact, are all associated with unusually high levels of Hb A2 in the heterozygous state.

scholarly journals An approximately 300 bp deletion involving part of the 5' beta-globin gene region is observed in members of a Turkish family with beta- thalassemia

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 583-586
Author(s):  
JC Diaz-Chico ◽  
KG Yang ◽  
A Kutlar ◽  
AL Reese ◽  
M Aksoy ◽  
...  
Keyword(s):  
Promoter Region ◽  
Genomic Dna ◽  
Restriction Site ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Promoter Sequences ◽  
Beta Globin Gene ◽  
Turkish Family ◽  
Thalassemia Trait

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.

scholarly journals Molecular characterization of a high A2 beta thalassemia by direct sequencing of single strand enriched amplified genomic DNA

Blood ◽  
1989 ◽  
Vol 73 (4) ◽  
pp. 924-930 ◽  
Author(s):  
SL Thein ◽  
C Hesketh ◽  
JM Brown ◽  
AV Anstey ◽  
DJ Weatherall
Keyword(s):  
Genomic Dna ◽  
Direct Sequencing ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Heterozygous State ◽  
Beta Globin ◽  
Anglo Saxon ◽  
Base Pairs ◽  
High Level ◽  
Endonuclease Mapping

Abstract Two families, one of Anglo-Saxon-Dutch descent, and the other, West Indian black, have an atypical beta thalassemia characterized by an unusually high level of Hb A2 in the heterozygous state. Restriction endonuclease mapping showed a deletion of about 1.35 kilobase (kb) in the 5′ region of the beta globin gene. Direct sequencing of a specific region of genomic DNA amplified by a new modification of the polymerase chain reaction defined the deletion to be 1,393 base pairs (bp) and to be the same in both families. The deletion extends from 485 bp 5′ to the mRNA CAP site to the middle of the second intervening sequence. This deletion, together with three others previously described that remove the 5′ end of the beta gene but leave the delta gene intact, are all associated with unusually high levels of Hb A2 in the heterozygous state.

Sign in / Sign up

Export Citation Format

Share Document