scholarly journals Severely Impaired Platelet Function Due to a Novel Mutation of P2Y12 from a Human Subject with No History of Bleeding

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1130-1130
Author(s):  
John C Kostyak ◽  
Carol A Dangelmaier ◽  
Benjamin R Mauri ◽  
Akruti Patel ◽  
Satya P. Kunapuli
Keyword(s):  
Human Subject ◽  
Conflicts Of Interest ◽  
Novel Mutation ◽  
Platelet Reactivity ◽  
Shape Change ◽  
Human Subjects ◽  
P2y12 Receptor ◽  
Heterozygous Mutation ◽  
Initial Stimulus ◽  
History Of

Abstract Platelets mediate hemostasis through amplifying an initial stimulus and aggregating at a site of injury. The identification of bleeding phenotypes in humans has the potential to reveal new insight into the mechanisms behind platelet signaling, as well as pinpoint new potential therapeutic targets. In fact, the study of bleeding disorders in human subjects has led to the identification of a number of disease states and proteins important to platelet functional responsiveness. We have recently identified a human subject (PDS25) with a platelet functional disorder that has a normal CBC, and no history of bleeding diathesis. However, platelets from PDS25 have virtually no response to even high concentrations of 2-MeSADP, even though P2Y12 protein expression appears unaltered (Figure 1). Further, platelet reactivity to high doses of agonist for other receptors, such as PAR-4 and GPVI, is normal. Low concentrations of these agonists, which typically rely on feedback for platelet reactivity, elicit an inhibited response using platelets from PDS25 compared to platelets from a healthy control. Consistently, Rap1b activity (Figure 2) was reduced in platelets from PDS25, while VASP phosphorylation was enhanced, suggesting that signaling from the P2Y12 receptor was interrupted by the heterozygous mutation. To determine whether it is the receptor or a downstream signaling component that is dysfunctional and because shape change in response to 2-MeSADP is normal in platelets from PDS25, we co-stimulated 2-MeSADP treated platelets with epinephrine to initiate signaling through Gz, which is very similar to Gi. We found that the response of platelets from PDS25 to 2-MeSADP can be rescued with the addition of epinephrine, suggesting that the signaling components downstream of Gi/zare intact. These data suggest that the aberrant reactivity observed in platelets from PDS25 is due to the P2Y12 receptor. Therefore, we performed a genetic analysis of P2Y12 from PDS25, which revealed a heterozygous mutation of D121N within the conserved DRY motif (Figure 3). We are currently evaluating how this heterozygous mutation confers such a strong phenotype. Disclosures No relevant conflicts of interest to declare.

Molecular Diagnosis of One Pedigree with Protein S Deficiency and Antithrombin Deficiency

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 5140-5140
Author(s):  
Rong-Fu Zhou ◽  
Hong Tao ◽  
Jian Ouyang ◽  
Xian Zhang ◽  
Yonggong Yang ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Novel Mutation ◽  
Color Doppler ◽  
Femoral Vein ◽  
Family Members ◽  
Protein S ◽  
Heterozygous Mutation ◽  
Sequencing Analysis ◽  
Antithrombin Deficiency ◽  
Exon 4

Abstract Abstract 5140 Objective To identify gene mutations for one patient and his family members with protein S and antithrombin deficiency. Methods ELISA were used to detect protein S (PS), protein C (PC) and antithrombin (AT) activities for the proband and family members, respectively. The genomic DNA was extracted from the peripheral blood of proband and family members. All exons and their flanks of protein S gene and antithrombin gene were amplified by polymerase chain reaction (PCR). The PCR products were sequenced directly. The mutation-related exons of his famliy members were amplified by PCR and sequenced directly. Results The proband was a 49-year-old male. He presented with sudden left lower extremity swelling and pain without casues. Regular examination revealed that his APTT, PT, and TT were all in normal levels, but D- dimmer was 5. 62mg/L, Color doppler ultrasonography showed thrombosis in his left femoral vein. The activity of PS for his family members was ‡1 0%, ‡2 0%, ‡3 0%, ‡4 130. 8%, ‡5 8. 4%, ‡1 0%, ‡2 0%, and that of AT was ‡1 129. 1%, ‡2 51. 9%, ‡3 73.2%, ‡4 119. 1%, ‡5 136. 2%, ‡1 65. 5% and ‡2 60. 1%, respectively. The sequencing analysis showed that a heterozygous missense mutation G68395T (NG_009813. 1) was detected in Exon 4 of PS gene leading to the substitution of Arg90 by Leu (NP_000304. 2) for the propositus. The heterozygous mutation (Arg90Leu) was also found in other family members. A heterozygous (nonsense) mutation G12444A (NG_012462. 1) was detected in Exon 4 of AT gene leading to Trp257Ter (NP_000479. 1) for the propositus. The mutation (Trp257Ter) was found in other family members with reduced activity of AT. These two mutations (G68395T in PS gene and G12444A in AT gene) were not reported before and were thus novel ones. Conclusion The novel mutation G68395T in PS gene and G12444A in AT gene might be the causes of deficiency of PS and AT for the family. Disclosures: No relevant conflicts of interest to declare.

Genetic and Phenotypic Analysis of Families with Inherited Hypo- and Dys-Fibrinogenemia. Fibrinogen Bratislava.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1794-1794
Author(s):  
Angelika Batorova ◽  
Daniela Horvathova ◽  
Martin Mistrik ◽  
Philippe de Moerloose ◽  
Marguerite Neerman-Arbez
Keyword(s):  
Genetic Analysis ◽  
Fibrinogen Level ◽  
Novel Mutation ◽  
Heterozygous Mutation ◽  
Blood Coagulation Disorders ◽  
Phenotypic Analysis ◽  
Spontaneous Bleeding ◽  
Exon 2 ◽  
Exon 1 ◽  
History Of

Abstract Inherited hypofibrinogenemia (hypo-FBG) and dysfibrinogenemia (dys-FBG) are rare blood coagulation disorders caused by quantitative or qualitative defects of fibrinogen. We reviewed the clinical course in 47 individuals with dys-FBG and 16 patients with hypo-FBG with median fibrinogen coagulant/antigen levels of 0.76/2.8 and 1.1/1.2 g/L, respectively. Genetic analysis was performed in 5 families (16 individuals) with dys-FBG and 4 families (8 individuals) with hypo-FBG. In the dysfibrinogenemia group 21 (45%) individuals were asymptomatic, 24(51%) patients suffered from bleeding and/or prolonged wound healing (only four had serious bleeding) and 2(4%) patients had a history of thrombosis. A total of 96 surgeries were performed without preoperative fibrinogen replacement in 31 dys-FBG patients, only 9 (9%) procedures were complicated with bleeding, two requiring fibrinogen substitution. Genetic analysis in dysfibrinogenemia has revealed heterozygous mutation in FGA exon 2 (Aα Arg16 His) known to cause delayed fibrinopeptide A cleavage by thrombin in 6 individuals (3 families). Five patients from two other families were heterozygous for a novel mutation in FGA exon 2 (Aα Gly13Glu). Fibrinogen coag/Ag median levels were comparable for both mutant genotypes: 0.5/2.9 g/L and 0.56/2.8 g/L, respectively. In the hypofibrinogenemia group 6/14 (43%) patients had mild spontaneous bleeding, 8/36 (22%) surgeries performed in 12 patients w/o replacement were complicated with bleeding. A novel mutation in FGG exon 1 (Trp3 Stop) was identified in heterozygosity for 3 patients (3 families) with FBG coag/Ag median level of 1.1/1.2 g/L. An additional unrelated patient with a fibrinogen level of 0.7 g/L and serious postpartum bleeding was heterozygous for a novel mutation in FGG exon 7 (Trp253Cys) - Fibrinogen Bratislava.

Novel Mutation in the Glycoprotein Ibβ in a Patient with Bernard-Soulier Syndrome: Possibility of Distant Parental Consanguinity

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4689-4689
Author(s):  
Rami Mahfouz ◽  
Carsten Bergmann ◽  
Zaher Otrock ◽  
Hanno Bolz ◽  
Samar A. Muwakkit
Keyword(s):  
Conflicts Of Interest ◽  
Novel Mutation ◽  
High Dose ◽  
Giant Platelets ◽  
Parental Consanguinity ◽  
Cell Counts ◽  
Platelet Disorder ◽  
Recurrent Epistaxis ◽  
History Of ◽  
Bernard Soulier Syndrome

Abstract Abstract 4689 Introduction: Bernard-Soulier syndrome (BSS) is a rare autosomal recessive disorder characterized by a prolonged skin-bleeding time and thrombocytopenia with giant platelets. The hallmark of BSS is an abnormal platelet attachment to the vessel wall due to reduced or abnormal glycoprotein (GP) Ib/IX/V complex. We present a case of BSS in a 14-month-old boy caused by a novel genetic mutation. Patient and methods: A 14-month-old Syrian boy was referred to our medical center with a history of easy bruisability, epistaxis, and low platelet counts since the age of 5 months. He was the second child of non-consanguineous parents. His parents and siblings were negative for a history of bleeding disorders. His nephew was reported to have low platelets counts. The patient was hospitalized in Syria several times and was initially diagnosed as having idiopathic thrombocytopenic purpura. He received corticosteroids and high-dose intravenous immunoglobulin both of which were ineffective. He also received platelet transfusion for recurrent epistaxis, which improved as per the parents. The possibility of a platelet disorder was raised and he was referred to our center for further investigation. Physical examination showed bruises over the face and extremities. Abdominal examination was negative for hepatosplenomegaly. There were no congenital abnormalities. His platelet count was 100 × 109/l. The presence of giant platelets was noted on blood film inspection. Other blood cell counts, blood chemistry and coagulation studies, including von Willebrand factor (vWF) antigen and activity, were within the normal range. A clinical diagnosis of BSS was made. Peripheral blood was obtained for genetic testing. DNA sequencing and analysis The initial extraction of the DNA material was done using the PEL-FREEZ extraction kit (PEL-FREEZ, DYNAL, USA) and genomic material stored at −80°C. We performed direct sequencing of the entire coding regions including exon-intron boundaries of the GPIbα and GPIbβ genes (GenBank: NM_000173.5 and NM_000407.4; mutation numbering + 1 corresponds to the A of the ATG-translation initiation codon, respectively). Genomic DNA from patient was amplified by PCR with oligonucleotide primers complementary to flanking intronic sequences. Primers were designed using the Primer3 program (http://www-genome.wi.mit.edu/cgi-bin/primer/primer3.cgi) (primer sequences and PCR conditions are available on request). PCR products were sequenced employing ABI BigDye chemistry (Applied Biosystems, Darmstadt, Germany). The same primers as for PCR were used as sequencing primers. Samples were run and analyzed on an ABI PRISM 3130 genetic analyzer (Applied Biosystems). Conclusion: We present a case of BSS in a 14-month-old boy caused by a novel nonsense mutation (c.423C>A) in the GPIbβ gene. Knowing that we are dealing with a very rare syndrome, the detected mutation in our patient was homozygous. Although the parents were non-consanguineous, we believe that they were related in a distant parental consanguinity which the parents and their family were not aware of. Disclosures: No relevant conflicts of interest to declare.

Effects of Strong P2Y12 Receptor Inhibition by Prasugrel on Platelet Inhibition During Endotoxemia: A Randomized Controlled Trial

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1245-1245
Author(s):  
Alexander O Spiel ◽  
Ulla Derhaschnig ◽  
Petra Jilma-Stohlawetz ◽  
Bernd Jilma
Keyword(s):  
Platelet Aggregation ◽  
Conflicts Of Interest ◽  
Platelet Reactivity ◽  
Controlled Trial ◽  
Platelet Inhibition ◽  
P2y12 Receptor ◽  
Reactivity Index ◽  
Double Blind ◽  
Plug Formation ◽  
Induced Aggregation

Abstract Abstract 1245 Background: P2Y12 receptor antagonists have become a mainstay for the treatment of cardiovascular diseases. Yet, they have rarely been evaluated under pathophysiological conditions apart from arterial diseases. Objectives: We hypothesized interactions between prasugrel and enhanced von Willebrand Factor (VWF) release in a model of systemic inflammation, and compared the pharmacodynamic effects of prasugrel versus placebo on agonist-induced platelet aggregation and shear-induced platelet plug formation. Subjects/Methods: Twenty healthy male volunteers were enrolled in a double-blind, placebo-controlled two-way cross-over trial. Each volunteer received either placebo or a 60 mg-loading dose of prasugrel two hours before endotoxin infusion. Platelet inhibition was measured with Multiple Electrode Aggregometry (MEA), the Platelet Function Analyzer-100 (PFA-100) and the Vasodilator Stimulated Phosphoprotein (VASP) phosphorylation assay, respectively. Results: Prasugrel reduced the platelet reactivity index in the VASP assay from 79% to 5–7%, and unequivocally prolonged the closure times of the Innovance cartridge to >300s, but also the CADP-CT to >300s in the majority of subjects. Prasugrel not only blunted platelet aggregation induced by ADP (−81%), but also other pathways including arachidonic acid (−60%), ristocetin (−75%; p<0.001 for all), and to a lesser degree collagen or thrombin receptor activating peptide (TRAP). Prasugrel decreased shear-induced platelet plug formation but VWF release during endotoxemia partly antagonized the inhibitory effect of prasugrel as measured with the PFA-100. Endotoxemia acutely decreased ristocetin and TRAP induced platelet aggregation, and enhanced ristocetin induced aggregation after 24h. Conclusions: These data for the first time demonstrate that strong in vivo blockade of P2Y12 by prasugrel inhibits a broad spectrum of platelet aggregation pathways. However, VWF release may reduce prasugrel's effects under high shear conditions. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Characterization of a Novel Mutation V136L in Bone Morphogenetic Protein 15 Identified in a Woman Affected by POI.

2021 ◽  
Author(s):  
Eleonora Ferrarini ◽  
Giuseppina De Marco ◽  
Francesca Orsolini ◽  
Elena Gianetti ◽  
Elena Benelli ◽  
...  
Keyword(s):  
Family History ◽  
Genetic Analysis ◽  
Autoimmune Diseases ◽  
Novel Mutation ◽  
Luciferase Reporter ◽  
Functional Study ◽  
Heterozygous Mutation ◽  
Normal Female ◽  
History Of

Abstract Background: Premature ovarian insufficiency (POI) is an ovarian defect characterized by primary or secondary amenorrhea, hypergonadotropism and hypoestrogenism which occurs before the age of 40 years with a major genetic component. In this study we performed clinical evaluation and genetic analysis of a group of 18 patients with POI.The study involved 18 consecutive women with POI. Karyotiping and genetic analysis for research of mutations in GDF9 (Growth Differentation Factor 9) and BMP15 (Bone morphogentic protein 15) genes and FMR1 (Fragile X Mental Retardation 1) premutation were carried out. In vitro functional study of the novel BMP15 mutation was performed using COV434 (Human ovarian granulosa tumour cells 434) cells of ovarian granulosa, which consistently express BMP responsive element, and luciferase reporter assay.Results: Three patients (17%) had a family history of POI. Ten patients (56%) had a family history of autoimmune diseases and nine patients (50%) showed a personal history of one or more autoimmune diseases. Of patients for whom morphological assessment was available, almost half (44%) had poor follicle assets or small ovaries’s size at pelvic US. Two patients (13%) showed reduced bone density at DEXA (Dual Energy X-ray Absorptiometry). All the women had normal female kariotype and no mutations in the GDF-9 gene or FMR1 premutations were found. A novel heterozygous mutation c.406G> C (V136L) of BMP15 gene was identified in one patient. After transfection in COV434 cells, BMP15 variant showed a significantly reduced luciferase activity compared to wild type. Conclusions: POI is a multifactorial disease with several health implications. Autoimmunity and genetics represent the most common aetiology. We identified and characterized a novel BMP15 mutation, providing an additional elucidation of molecular basis of this complex disorder.

scholarly journals Characterization of a novel mutation V136L in bone morphogenetic protein 15 identified in a woman affected by POI

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Eleonora Ferrarini ◽  
Giuseppina De Marco ◽  
Francesca Orsolini ◽  
Elena Gianetti ◽  
Elena Benelli ◽  
...  
Keyword(s):  
Family History ◽  
Genetic Analysis ◽  
Autoimmune Diseases ◽  
Novel Mutation ◽  
Luciferase Reporter ◽  
Functional Study ◽  
Heterozygous Mutation ◽  
Normal Female ◽  
History Of

Abstract Background Premature ovarian insufficiency (POI) is an ovarian defect characterized by primary or secondary amenorrhea, hypergonadotropism and hypoestrogenism which occurs before the age of 40 years with a major genetic component. In this study we performed clinical evaluation and genetic analysis of a group of 18 patients with POI. The study involved 18 consecutive women with POI. Karyotiping and genetic analysis for research of mutations in GDF9 (Growth Differentation Factor 9) and BMP15 (Bone morphogentic protein 15) genes and FMR1 (Fragile X Mental Retardation 1) premutation were carried out. In vitro functional study of the novel BMP15 mutation was performed using COV434 (Human ovarian granulosa tumour cells 434) cells of ovarian granulosa, which consistently express BMP responsive element, and luciferase reporter assay. Results Three patients (17%) had a family history of POI. Ten patients (56%) had a family history of autoimmune diseases and nine patients (50%) showed a personal history of one or more autoimmune diseases. Of patients for whom morphological assessment was available, almost half (44%) had poor follicle assets or small ovaries’s size at pelvic US. Two patients (13%) showed reduced bone density at DEXA (Dual Energy X-ray Absorptiometry). All the women had normal female kariotype and no mutations in the GDF-9 gene or FMR1 premutations were found. A novel heterozygous mutation c.406G > C (V136L) of BMP15 gene was identified in one patient. After transfection in COV434 cells, BMP15 variant showed a significantly reduced luciferase activity compared to wild type. Conclusions POI is a multifactorial disease with several health implications. Autoimmunity and genetics represent the most common aetiology. We identified and characterized a novel BMP15 mutation, providing an additional elucidation of molecular basis of this complex disorder.

scholarly journals Identification of a Novel Missense KRT12 Mutation in a Vietnamese Family with Meesmann Corneal Dystrophy

2020 ◽  
Vol 11 (1) ◽  
pp. 120-126
Author(s):  
Pham Ngoc Dong ◽  
Le Xuan Cung ◽  
Tran Khanh Sam ◽  
Do Thi Thuy Hang ◽  
Doug D. Chung ◽  
...  
Keyword(s):  
Sanger Sequencing ◽  
Novel Mutation ◽  
Family Members ◽  
Corneal Dystrophy ◽  
Slit Lamp ◽  
Slit Lamp Examination ◽  
Corneal Epithelial ◽  
Epithelial Phenotype ◽  
History Of ◽  
Characteristic Features

Meesmann epithelial corneal dystrophy (MECD) is a rare dominantly inherited disorder that is characterized by corneal epithelial microcysts and is associated with mutations in the keratin 3 (KRT3) and keratin 12 (KRT12) genes. In this study, we report a novel mutation in the KRT12 gene in a Vietnamese pedigree with MECD. Slit-lamp examination was performed on each of the 7 recruited members of a Vietnamese family to identify characteristic features of MECD. After informed consent was obtained from each individual, genomic DNA was isolated from saliva samples and screening of KRT3and KRT12 genes was performed by Sanger sequencing. The proband, a 31-year-old man, complained of a 1-year history of eye irritation and photophobia. Slit-lamp examination revealed intraepithelial microcysts involving only the corneal periphery in each eye with clear central corneas and no stromal or endothelial involvement. Three family members demonstrated similar intraepithelial microcysts, but with diffuse involvement, extended from limbus to limbus. Sanger sequencing of KRT3 (exon 7) and KRT12 (exons 1 and 6) in the proband revealed a novel heterozygous KRT12 variant (c.1273G>A [p.Glu425Lys]) that was present in the three affected family members but was absent in the three family members with clear corneas. This study is the first report of a Vietnamese family affected with MECD, associated with an atypical peripheral corneal epithelial phenotype in the proband and a novel mutation in KRT12.

scholarly journals Novel mutation in the TGFBI gene in a Moroccan family with atypical corneal dystrophy: a case report

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yahya Benbouchta ◽  
Imane Cherkaoui Jaouad ◽  
Habiba Tazi ◽  
Hamza Elorch ◽  
Mouna Ouhenach ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Clinical Symptoms ◽  
Age Of Onset ◽  
Novel Mutation ◽  
Corneal Dystrophy ◽  
Heterozygous Mutation ◽  
Large Variability ◽  
Whole Exome ◽  
Moroccan Family

Abstract Background Corneal dystrophies (CDs) are a heterogeneous group of bilateral, genetically determined, noninflammatory bilateral corneal diseases that are usually limited to the cornea. CD is characterized by a large variability in the age of onset, evolution and visual impact and the accumulation of insoluble deposits at different depths in the cornea. Clinical symptoms revealed bilateral multiple superficial, epithelial, and stromal anterior granular opacities in different stages of severity among three patients of this family. A total of 99 genes are involved in CDs. The aim of this study was to identify pathogenic variants causing atypical corneal dystrophy in a large Moroccan family and to describe the clinical phenotype with severely different stages of evolution. Case presentation In this study, we report a large Moroccan family with CD. Whole-exome sequencing (WES) was performed in the three affected members who shared a phenotype of corneal dystrophy in different stages of severity. Variant validation and familial segregation were performed by Sanger sequencing in affected sisters and mothers and in two unaffected brothers. Whole-exome sequencing showed a novel heterozygous mutation (c.1772C > A; p.Ser591Tyr) in the TGFBI gene. Clinical examinations demonstrated bilaterally multiple superficial, epithelial and stromal anterior granular opacities in different stages of severity among three patients in this family. Conclusions This report describes a novel mutation in the TGFBI gene found in three family members affected by different phenotypic aspects. This mutation is associated with Thiel-Behnke corneal dystrophy; therefore, it could be considered a novel phenotype genotype correlation, which will help in genetic counselling for this family.

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