Case 6: A 2-year-old boy with mucocutaneous bleeding – Glanzmann’s Thrombasthenia. The role of the fibrinogen-receptor glycoprotein IIb–IIIa in platelet function

1999 ◽  
Vol 56 (9) ◽  
pp. 495-498
Author(s):  
Alberio ◽  
Hirt

Der Fall eines Patienten mit einer seit Geburt vorhandenen mukokutanen Blutungsneigung wird vorgestellt. Es wurde eine Thrombasthenie Glanzmann diagnostiziert. An diesem Beispiel werden wichtige Aspekte der Diagnostik und Therapie von Thrombozytenfunktionsstörungen beschrieben. Zudem wer-den die Thrombozytenbeteiligung im Blutstillungsvorgang sowie die Rolle des thrombozytären Fibrinogen-Rezeptors Glykoprotein IIb–IIIa im Rahmen der primären Hämostase dargestellt.

2018 ◽  
Vol 2 (02) ◽  
pp. 59-60
Author(s):  
Farida Yasmin ◽  
Md. Anwarul Karim ◽  
Chowdhury Yakub Jamal ◽  
Mamtaz Begum ◽  
Ferdousi Begum

Epistaxis in children is one of the important presenting symptoms for attending emergency department in paediatric patients. Recurrent epistaxis is common in children. Although epistaxis in children usually occurred due to different benign conditions, it may be one of the important presenting symptoms of some inherited bleeding disorder. Whereas most bleeding disorders can be diagnosed through different standard hematologic assessments, diagnosing rare platelet function disorders may be challenging. In this article we describe one case report of platelet function disorders on Glanzmann’s thrombasthenia (GT). Our patient was a 10-year old girl who presented to us with history of recurrent severe epistaxis. She had a bruise on her abdomen and many scattered petechiae in different parts of the body. Her previous investigations revealed no demonstrable haemostatic anomalies. After performing platelet aggregation test, she was diagnosed as GT.


1979 ◽  
Author(s):  
E.F. von Leeuwen ◽  
G.T.E. Zonneveld ◽  
L.E. von Riesz ◽  
C.S.P Jenkins ◽  
J.A. van Mourik ◽  
...  

The expression of the platelet-speciftc alloantigens on the platelets from 6 patients with Glanzmann’s Thrombasthenia (G.T.) and their nearest relatives was studied. The alloantigens Zwa (PIAl) and Zwb(PIA2) were found to be completely absent from thrombasthenic platelets while the alloantigens of the Ko-system were found to be normally expressed. The alloantigen Baka(phenotypefrequency 90.2%) was absent on the platelets from 4 studied G.T. patients. The platelets of all the family members reacted positively with anti-Zwa, negatively with antt-Zwb serum. SDS-PA gel electrophoresis of G.T. platelet membranes demonstrated a marked deficiency of the glycoproteins IIb and IIIa. Glycoprotein analysis of the platelet membranes from the family members of 3 of the 6 patients reveoled no apparent abnormalities.Pre-incubation with anti-Zwa containing plasma strongly inhibits ADP-and collagen induced aggregation of platelets from normal Zwa homozygous individuols with a slight inhibition of the aggregation induced by ristocetin. Zwa antibodies did not affect the functions of platelets from ZWb homozygous individuals. Thus binding of Zwa antibodies induces a thrombosthenis-like state.


Blood ◽  
1990 ◽  
Vol 75 (4) ◽  
pp. 881-888 ◽  
Author(s):  
PF Bray ◽  
MA Shuman

The platelet fibrinogen receptor, which is composed of glycoproteins IIb (GPIIb) and IIIa (GPIIIa), belongs to a large family of receptors that participate in a multitude of biologically important adhesive interactions. Platelets from most patients with the autosomal recessive bleeding disorder, Glanzmann's thrombasthenia, are deficient in GPIIb and GPIIIa. We have used cDNA probes to analyze the GPIIb and GPIIIa genes in four patients from three kindreds with Glanzmann's thrombasthenia. Southern analysis of their DNA was identical to that observed in normals when probed with a full-length GPIIb cDNA or a 3′ GPIIIa cDNA. However, in one family, a 5′ 2.0 kb GPIIIa cDNA identified abnormal DNA fragments in the father and two affected siblings' genes. A series of restriction digests resulting in small genomic fragments were probed with portions of the 5′ 2.0 kb GPIIIa cDNA and indicated that the abnormal sequences are flanked by normal fragments of the GPIIIa gene. To analyze further the genetic defect in this family, RNA was prepared from their platelets. Northern analysis revealed normal levels of GPIIb mRNA compared to control platelets. We were unable to identify GPIIIa mRNA of any size in the clinically affected family members. We also identified an EcoRI restriction fragment length polymorphism (RFLP) that permitted carrier status determination in the clinically unaffected siblings. These studies indicate that Glanzmann's thrombasthenia can be caused by heterogeneous defects in the GPIIIa gene. Furthermore, we have shown that platelets can be used to characterize normal and abnormal GPIIIa and GPIIb mRNA, and RFLPs may be used to determine the carrier status in some families with Glanzmann's thrombasthenia. The specific gene abnormality in this family appears to represent an example of an insertional mutation resulting in a human disease.


Blood ◽  
1990 ◽  
Vol 75 (4) ◽  
pp. 881-888 ◽  
Author(s):  
PF Bray ◽  
MA Shuman

Abstract The platelet fibrinogen receptor, which is composed of glycoproteins IIb (GPIIb) and IIIa (GPIIIa), belongs to a large family of receptors that participate in a multitude of biologically important adhesive interactions. Platelets from most patients with the autosomal recessive bleeding disorder, Glanzmann's thrombasthenia, are deficient in GPIIb and GPIIIa. We have used cDNA probes to analyze the GPIIb and GPIIIa genes in four patients from three kindreds with Glanzmann's thrombasthenia. Southern analysis of their DNA was identical to that observed in normals when probed with a full-length GPIIb cDNA or a 3′ GPIIIa cDNA. However, in one family, a 5′ 2.0 kb GPIIIa cDNA identified abnormal DNA fragments in the father and two affected siblings' genes. A series of restriction digests resulting in small genomic fragments were probed with portions of the 5′ 2.0 kb GPIIIa cDNA and indicated that the abnormal sequences are flanked by normal fragments of the GPIIIa gene. To analyze further the genetic defect in this family, RNA was prepared from their platelets. Northern analysis revealed normal levels of GPIIb mRNA compared to control platelets. We were unable to identify GPIIIa mRNA of any size in the clinically affected family members. We also identified an EcoRI restriction fragment length polymorphism (RFLP) that permitted carrier status determination in the clinically unaffected siblings. These studies indicate that Glanzmann's thrombasthenia can be caused by heterogeneous defects in the GPIIIa gene. Furthermore, we have shown that platelets can be used to characterize normal and abnormal GPIIIa and GPIIb mRNA, and RFLPs may be used to determine the carrier status in some families with Glanzmann's thrombasthenia. The specific gene abnormality in this family appears to represent an example of an insertional mutation resulting in a human disease.


1987 ◽  
Author(s):  
R M Hardisty ◽  
A Pannocchia ◽  
N Mahmood ◽  
T J C Nokes ◽  
D Pidard ◽  
...  

A 17-year-old Italian boy has had a lifelong bleeding tendency, with frequent epistaxes and gum bleeding. The bleeding time is prolonged and the platelet count low normal. Electron microscopy showed a wide diversity of platelet size with many giant forms. In citrated PRP, ADP and other agonists induce slow and incomplete aggregation. The response of washed platelets varied with the agonist but ranged from subnormal to almost normal. Fibrinogen binding to washed platelets occurred slowly in response to ADP but eventually approached normal levels. No significant abnormality was observed of 5HT uptake, adenine nucleotide content, platelet factor-3 availability, β-thromboglobulin content or release, or malonyldialdehyde production. Clot retraction was normal. SDS-PAGE showed reduced amounts of GPIIb and GPU Ia. Crossed immunoelectrophoresis of Triton X-100 extracts of washed platelets showed the presence of GPIIb/IIIa complexes at 25-50% of normal levels. SDS-PAGE combined with an immunoblot procedure confirmed unchanged mobilities of GPIIb and GPIIIa and a normal proportion of GPIIb to GPIIIa. However, binding studies with radiolabelled monoclonal antibodies showed that intact washed platelets expressed only 12-20% of the normal binding sites for M148, AP-2 and Tab. These antibodies recognize different epitopes on GPIIb/lIIa complexes. Similar levels of these glycoproteins were detected by autoradiography after SDS-PAGE of radio-iodinated patient's platelets. GP lb was normally present. A possible defect in the exposure of fibrinogen binding sites might contribute to the altered platelet function. Meanwhile, the patient appears to be a unique variant of Glanzmann's thrombasthenia with GP IIb/IIIa complexes at the borderline of those able to support platelet aggregation.


2002 ◽  
Vol 87 (06) ◽  
pp. 1034-1042 ◽  
Author(s):  
Giovanna D’Andrea ◽  
Donatella Colaizzo ◽  
Gennaro Vecchione ◽  
Elvira Grandone ◽  
Giovanni Di Minno ◽  
...  

SummaryGlanzmann’s thrombasthenia (GT) is a genetically heterogeneous autosomal recessive syndrome associated with a bleeding tendency. To elucidate molecular basis of GT we have screened for mutations 30 GT patients. On the whole, 21 different candidate causal mutations, 17 in the αIIb and 4 in the β3 gene have been found. Only two (αIIb Pro145Ala and IVS3(−3)-418del) have been previously reported. Nine mutations (42.9%) were likely to produce truncated proteins, whereas the remaining 12 were missense mutations that affected highly conserved residues in αIIb and β3 genes. Six mutations were found in different patients suggesting a possible founder effect. The wide spectrum of expressivity, ranging from mild to severe also among patients carrying the same mutations, provided evidence for a role of different loci or circumstantial factors. In conclusion, we have identified a spectrum of unreported mutations that may be of value to unravel the role of specific regions of αIIb and β3 genes.


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