scholarly journals Glanzmann's thrombasthenia associated with deletion-insertion and alternative splicing in the glycoprotein IIb gene

Blood ◽  
1995 ◽  
Vol 85 (2) ◽  
pp. 414-420 ◽  
Author(s):  
H Peretz ◽  
N Rosenberg ◽  
S Usher ◽  
E Graff ◽  
PJ Newman ◽  
...  

Glanzmann's thrombasthenia is a bleeding disorder characterized by a decrease or absence of the functional platelet membrane glycoprotein (GP) complex, GPIIb/IIIa (alpha IIb beta 3). We describe a new deletion- insertion mutation in the GPIIb gene causing type I Glanzmann's thrombasthenia in two siblings of a consanguineous Iranian-Jewish family. The proband's platelets bound more antibodies against the vitronectin receptor-alpha V beta 3 than normal platelets, suggesting a normal GPIIIa (beta 3) gene and a defect in the GPIIb gene. Sequencing of amplified cDNA and genomic DNA fragments showed a 6-bp deletion and 31-bp insertion in exon 25 of the GPIIb gene. The predominant platelet GPIIb mRNA of the proband was a product of the splicing of exon 24 to a cryptic AG acceptor site in the insertion and encoded for deletion of amino acids Leu817-Asn826 and insertion of eight different amino acids. Cotransfection of COS-7 cells with expression vectors containing wild- type GPIIIa cDNA and the mutated GPIIb cDNA failed to produce detectable amounts of GPIIb/IIIa on the surface of the cells. Allele- specific restriction analysis of genomic DNA of family members showed homozygosity for the mutation in the affected siblings, heterozygosity in the parents, and homozygosity for the normal allele in an unaffected sibling. The observed mutation is in a region that is conserved from rodents to humans and has been suggested to be involved in the interaction between GPIIb and GPIIIa when these GPs are complexed in solution.

Blood ◽  
1995 ◽  
Vol 85 (2) ◽  
pp. 414-420 ◽  
Author(s):  
H Peretz ◽  
N Rosenberg ◽  
S Usher ◽  
E Graff ◽  
PJ Newman ◽  
...  

Abstract Glanzmann's thrombasthenia is a bleeding disorder characterized by a decrease or absence of the functional platelet membrane glycoprotein (GP) complex, GPIIb/IIIa (alpha IIb beta 3). We describe a new deletion- insertion mutation in the GPIIb gene causing type I Glanzmann's thrombasthenia in two siblings of a consanguineous Iranian-Jewish family. The proband's platelets bound more antibodies against the vitronectin receptor-alpha V beta 3 than normal platelets, suggesting a normal GPIIIa (beta 3) gene and a defect in the GPIIb gene. Sequencing of amplified cDNA and genomic DNA fragments showed a 6-bp deletion and 31-bp insertion in exon 25 of the GPIIb gene. The predominant platelet GPIIb mRNA of the proband was a product of the splicing of exon 24 to a cryptic AG acceptor site in the insertion and encoded for deletion of amino acids Leu817-Asn826 and insertion of eight different amino acids. Cotransfection of COS-7 cells with expression vectors containing wild- type GPIIIa cDNA and the mutated GPIIb cDNA failed to produce detectable amounts of GPIIb/IIIa on the surface of the cells. Allele- specific restriction analysis of genomic DNA of family members showed homozygosity for the mutation in the affected siblings, heterozygosity in the parents, and homozygosity for the normal allele in an unaffected sibling. The observed mutation is in a region that is conserved from rodents to humans and has been suggested to be involved in the interaction between GPIIb and GPIIIa when these GPs are complexed in solution.


Blood ◽  
1997 ◽  
Vol 90 (2) ◽  
pp. 669-677 ◽  
Author(s):  
Marie-Christine Morel-Kopp ◽  
Cécile Kaplan ◽  
Valérie Proulle ◽  
Vincent Jallu ◽  
Chantal Melchior ◽  
...  

Abstract Glanzmann's thrombasthenia (GT) is a recessive autosomal bleeding disorder characterized by abnormal platelet aggregation due to a qualitative or quantitative defect of the glycoprotein (GP) IIb-IIIa complex (integrin αIIbβ3). We describe a new mutation in the GPIIIa gene responsible for type I GT in a consanguineous Algerian family. A discordance between phenotyping and genotyping of the GPIIIa-related HPA-1 platelet alloantigen system in three family members heterozygous for the disease suggested a genetic defect in the GPIIIa gene and a normal GPIIb gene. Sequence analysis of amplified genomic DNA fragments showed a 6-bp deletion in exon 7 of the GPIIIa gene resulting in the amino acid deletion/substitution (Ile325Pro326Gly327 → Met) and creating a new BspHI restriction site. Expression of the mutated integrin β3 subunit cDNA in Chinese hamster ovary cells showed that the cDNA gene was transcribed into a full-length β3 protein with an apparent molecular weight identical to wild-type β3 and accumulated as a single-chain molecule in the cell cytoplasm. The absence of heterodimeric complex formation of the mutant β3 protein with endogeneous αv was shown by immunoprecipitation experiments, intracellular immunofluorescent labeling, and a semiquantitative enzyme-linked immunosorbent assay using the αvβ3 complex-specific monoclonal antibodies LM609 and 23C6. Substitution of the methionine residue by a proline, present at position 326 of wild-type β3, did not restore the ability of the recombinant mutant β3 protein to associate with αv, suggesting that the Ile-Pro-Gly motif is located in a β3 domain important for integrin subunit interaction. The association of a BspHI restriction site with this newly identified mutation has allowed allele-specific restriction analysis of Algerian GT individuals and the identification of two new unrelated type I patients exhibiting the same mutation, suggesting that the described mutation might be significant in this population and that BspHI restriction analysis will provide a useful screening assay for antenatal diagnosis and genetic counselling.


Blood ◽  
1997 ◽  
Vol 90 (2) ◽  
pp. 669-677 ◽  
Author(s):  
Marie-Christine Morel-Kopp ◽  
Cécile Kaplan ◽  
Valérie Proulle ◽  
Vincent Jallu ◽  
Chantal Melchior ◽  
...  

Glanzmann's thrombasthenia (GT) is a recessive autosomal bleeding disorder characterized by abnormal platelet aggregation due to a qualitative or quantitative defect of the glycoprotein (GP) IIb-IIIa complex (integrin αIIbβ3). We describe a new mutation in the GPIIIa gene responsible for type I GT in a consanguineous Algerian family. A discordance between phenotyping and genotyping of the GPIIIa-related HPA-1 platelet alloantigen system in three family members heterozygous for the disease suggested a genetic defect in the GPIIIa gene and a normal GPIIb gene. Sequence analysis of amplified genomic DNA fragments showed a 6-bp deletion in exon 7 of the GPIIIa gene resulting in the amino acid deletion/substitution (Ile325Pro326Gly327 → Met) and creating a new BspHI restriction site. Expression of the mutated integrin β3 subunit cDNA in Chinese hamster ovary cells showed that the cDNA gene was transcribed into a full-length β3 protein with an apparent molecular weight identical to wild-type β3 and accumulated as a single-chain molecule in the cell cytoplasm. The absence of heterodimeric complex formation of the mutant β3 protein with endogeneous αv was shown by immunoprecipitation experiments, intracellular immunofluorescent labeling, and a semiquantitative enzyme-linked immunosorbent assay using the αvβ3 complex-specific monoclonal antibodies LM609 and 23C6. Substitution of the methionine residue by a proline, present at position 326 of wild-type β3, did not restore the ability of the recombinant mutant β3 protein to associate with αv, suggesting that the Ile-Pro-Gly motif is located in a β3 domain important for integrin subunit interaction. The association of a BspHI restriction site with this newly identified mutation has allowed allele-specific restriction analysis of Algerian GT individuals and the identification of two new unrelated type I patients exhibiting the same mutation, suggesting that the described mutation might be significant in this population and that BspHI restriction analysis will provide a useful screening assay for antenatal diagnosis and genetic counselling.


1991 ◽  
Vol 66 (04) ◽  
pp. 500-504 ◽  
Author(s):  
H Peretz ◽  
U Seligsohn ◽  
E Zwang ◽  
B S Coller ◽  
P J Newman

SummarySevere Glanzmann's thrombasthenia is relatively frequent in Iraqi-Jews and Arabs residing in Israel. We have recently described the mutations responsible for the disease in Iraqi-Jews – an 11 base pair deletion in exon 12 of the glycoprotein IIIa gene, and in Arabs – a 13 base pair deletion at the AG acceptor splice site of exon 4 on the glycoprotein IIb gene. In this communication we show that the Iraqi-Jewish mutation can be identified directly by polymerase chain reaction and gel electrophoresis. With specially designed oligonucleotide primers encompassing the mutation site, an 80 base pair segment amplified in healthy controls was clearly distinguished from the 69 base pair segment produced in patients. Patients from 11 unrelated Iraqi-Jewish families had the same mutation. The Arab mutation was identified by first amplifying a DNA segment consisting of 312 base pairs in controls and of 299 base pairs in patients, and then digestion by a restriction enzyme Stu-1, which recognizes a site that is absent in the mutant gene. In controls the 312 bp segment was digested into 235 and 77 bp fragments, while in patients there was no change in the size of the amplified 299 bp segment. The mutation was found in patients from 3 out of 5 unrelated Arab families. Both Iraqi-Jewish and Arab mutations were detectable in DNA extracted from blood and urine samples. The described simple methods of identifying the mutations should be useful for detection of the numerous potential carriers among the affected kindreds and for prenatal diagnosis using DNA extracted from chorionic villi samples.


1995 ◽  
Vol 73 (05) ◽  
pp. 756-762 ◽  
Author(s):  
Yoshiaki Tomiyama ◽  
Hirokazu Kashiwagi ◽  
Satoru Kosugi ◽  
Masamichi Shiraga ◽  
Yoshio Kanayama ◽  
...  

SummaryWe analyzed the molecular genetic defect responsible for type I Glanzmann’s thrombasthenia in a Japanese patient. In an immunoblot assay using polyclonal anti-GPIIb-IIIa antibodies, some GPIIIa (15% of normal amount) could be detected in the patient’s platelets, whereas GPIIb could not (<2% of normal amount). Nucleotide sequence analysis of platelet GPIIb mRNA-derived polymerase chain reaction (PCR) products revealed that patient’s GPIIb cDNA had a 75-bp deletion in the 3’ boundary of exon 17 resulting in an in-frame deletion of 25 amino acids. DNA analysis and family study revealed that the patient was a compound heterozygote of two GPIIb gene defects. One allele derived from her father was not expressed in platelets, and the other allele derived from her mother had a 9644C → T mutation which was located at the position -3 of the splice donor junction of exon 17 and resulted in a termination codon (TGA). Moreover, quantitative analysis demonstrated that the amount of the abnormal GPIIb transcript in the patient’s platelets was markedly reduced. Thus, the C → T mutation resulting in the abnormal splicing of GPIIb transcript and the reduction in its amount is responsible for Glanzmann’s thrombasthenia.


1983 ◽  
Vol 49 (03) ◽  
pp. 182-186
Author(s):  
G T E Zonneveld ◽  
E F van Leeuwen ◽  
A Sturk ◽  
J W ten Cate

SummaryQuantitative glycoprotein (GP) analysis of whole platelets or platelet membranes was performed by SDS-polyacrylamide gelelectrophoresis (SDS-PAGE) and periodic acid Schiff staining in the families of two unrelated Glanzmann’s thrombasthenia (GT) patients. Each family consisted of two symptom free parents, a symptom free daughter and a GT daughter. All symptom free members had a normal bleeding time, clot retraction and platelet aggregation response to adenosine 5’-diphosphate (ADP), collagen and adrenalin. Platelet Zw* antigen was normally expressed in these subjects. GT patiens, classified as a type I and II subject, showed reduced amounts of GP lib and of GP nia. Analysis of isolated membranes in the non-reduced state, however, showed that the amount of GP Ilia was also reduced in three of the four parents, whereas one parent (of the GT type I patient) and the two unaffected daughters had normal amounts of GP Ilia. Quantitative SDS-PAGE may therefore provide a method for the detection of asymptomatic carriers in GT type I and II.


Blood ◽  
1992 ◽  
Vol 79 (12) ◽  
pp. 3212-3218 ◽  
Author(s):  
A Kato ◽  
K Yamamoto ◽  
S Miyazaki ◽  
SM Jung ◽  
M Moroi ◽  
...  

Abstract The genetic basis for Glanzmann's thrombasthenia (GT) was elucidated on a compound heterozygote with glycoprotein (GP)IIb gene: an opal mutation at the end of exon 17 (CGA----TGA) results in only a trace amount of GPIIb mRNA, and a splicing mutation at the acceptor site of exon 26 (CAG----GAG) causes an in-frame, exon skipping process from exon 25 to 27. This aberrant transcript encodes a single-chain polypeptide characterized by a 42-amino acid deletion, which includes the proteolytic cleavage site(s) and a unique, proline-rich region at the location corresponding to the carboxyl-terminal of the normal GPIIb alpha-chain. These characteristics are shared by a previously reported defective GPIIb molecule, which is neither assembled with GPIIIa nor transported to the cellular surface. Despite its normal transcription level, expression of the present defective GPIIb molecule was significantly decreased (approximately 6% of the control level). Because the precursor GPIIb molecule is assembled with GPIIIa in the endoplasmic reticulum (ER) and its processing, as well as stability, is dependent on the GPIIIa subunit, the defective GPIIb molecule may be rapidly degraded by the intrinsic quality control system of the ER due to its inability to form a stable heterodimer complex as a consequence of its misfolded structure. Although we did not confirm that the GPIIIa genes of this individual were normal, GPIIIa may be secondarily decreased (approximately 11% of control), because a large part of it could not be complexed, making it vulnerable to proteolysis. To elucidate the molecular basis for GT, we propose here a classification of GT based on the biosynthetic pathway of the GPIIb-IIIa complex.


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