Autosomal Recessive Bleeding Disorder Research Articles

Hereditary coagulation factor VII deficiency caused by novel compound heterozygous mutations c.572-1G>A and c.1037A>C in a Chinese pedigree

Hereditary coagulation factor VII (FVII) deficiency is a rare autosomal recessive bleeding disorder. The aims of this study were to identify and verify the pathogenic mutation sites in a family with hereditary coagulation FVII deficiency, and preliminarily explore the underlying mechanisms. We identified a novel combination of compound heterozygous mutations, c.572-1G>A and c.1037A>C in F7 gene, associated with FVII deficiency. The splice site mutation c.572-1G>A led to a truncation, resulting in the loss of the essential catalytic domain of the FVII protein. The c.1037A>C missense mutation has not been previously reported. Our study revealed that this mutation leads to steric hindrance between residues, causing significant changes in the energy and structure of the FVII protein, ultimately affecting its function. These changes disrupt the normal function of the FVII protein, accelerating the development of inherited FVII deficiency. Moreover, the mRNA expression of the F7 gene and the protein expression of the FVII antigen (FVII: Ag) were significantly lower in the proband, as well as in the proband's parents, compared to the healthy control (P<0.05). Our findings not only elucidate the genetic underpinning of FVII deficiency in the family studied but also contribute a new mutation to the known disease spectrum, potentially assisting in future diagnostic and therapeutic approaches.

Factor X deficiency: An overlooked cause of bleeding in the newborn

Abstract Inherited factor X (FX) deficiency is a rare autosomal recessive bleeding disorder, presenting with various bleeding manifestations ranging from nonspecific bruising to life-threatening intracranial hemorrhage. It is often misdiagnosed as hemorrhagic disease of the newborn. It is characterized by prolonged prothrombin time, as well as activated partial thromboplastin time, and needs FX level assay for definitive diagnosis. Here, we describe a case of a newborn with FX deficiency who presented with frank umbilical stump bleeding.

Pregnancy and Delivery Outcome Among Ladies with Glanzmann Thrombasthenia: A Report from Glanzmann Thrombasthenia Registry of Al-Madinah, Saudi Arabia

Introduction Glanzmann's thrombasthenia (GT) is an autosomal recessive bleeding disorder due to functional platelet defects impairing platelet aggregation. AlMadinah has reported the highest prevalence of GT globally, with a prevalence of 1:10,000. Pregnancy had been reported among ladies with GT with different outcomes. As a bleeding disorder, Pregnancy among ladies with GT carries a higher risk for bleeding either during pregnancy or intra and postpartum. Neonates have an increased risk for hemorrhage, either due to alloimmunization or they may carry the gene of GT. Many GT ladies got pregnant earlier when GT diagnosis was difficult, and they did not know their diagnosis; even after the diagnosis was possible, ceasing the menstrual cycle was not culturally acceptable. In this study, we are describing the pregnancies among GT ladies and their outcomes. Methods This is a report from the AlMadinah GT registry in the Madinah Hemophilia Comprehensive Care Center. The registry covers a period of 20 years and includes all patients with a confirmed diagnosis of GT. 136 GT patients were identified. 11 patients had no data available. A spreadsheet designed to collect detailed data about pregnancy, delivery, and neonates. Electronic and hard copy medical records have been accessed to collect data. Data was analyzed by the statistical package of social sciences (SPSS) version 23. The research and ethical committee approved the study. Results Twenty-eight pregnancies have been identified. The median age of mothers at the time of pregnancy was 30 ± 5.7 years (20 - 42 years). Mothers' Gravidity was 1-7 (median 2.5 ± 1.6), and parity was 1-6 (median 2 ±1.4). Five miscarriages (18%) identified occurred at the 17 th, 11 th, 13 th and 15 th gestational weeks. In contrast, 5 th one is not on record. Three miscarriages took place after moderate to severe vaginal bleeding. Mild to severe post-abortion bleeding was controlled with platelets transfusion, activated human recombinant factor 7 (rFVIIa), and tranexamic acid. Thirty-two bleeding episodes occurred during 16 pregnancies, with 1-5 bleeding episodes per pregnancy (Median of 2 episodes). Seven (22%) bleeding episodes were vaginal bleeds, while 25 (78%) were GT-related bleeds such as gum bleeding or epistaxis. Two patients must undergo plasma exchange and be on steroids due to alloimmunization development during pregnancy. Delivery occurred at the gestational age of 34-40 weeks (median 38 ± 2 weeks). Sixteen (70%) deliveries were vaginal, and 7(30%) were cesarean sections. The indications for cesarean sections were family request in 4 cases, fetal distress in two instances, and precautional section in one case. Prophylactic platelets transfusion had given pre-delivery on four occasions, rFVIIa on 4, and a combination of rFVIIa and platelets transfusion on six occasions. Tranexamic acid was used in all cases. Ten deliveries were conducted with no prophylaxis. Post-partum hemorrhage (PPH) occurred in 18 (64%) cases, 13 (72%) cases of primary PPH, and 5 (28%) cases of secondary PPH. We could not find a correlation between pre-delivery prophylaxes and PPH (P=0.2). PPH had controlled successfully with platelets transfusion and rFVIIa though red blood cell transfusion was needed on eight occasions. Twenty-eight pregnancies produced 24 babies (13 girls and 11 boys). Four babies had bleeding (2 intracranial hemorrhages, one subdural hematoma, and one gum oozing), and 9 had alloimmunization with mild to severe thrombocytopenia. Of all babies tested for GT, 6 of them were GT. Conclusions Pregnancy among ladies with GT carries a higher risk of bleeding. Management of pregnancy in women with GT has to be in a Multidisciplinary approach. The high rate of PPH among GT ladies makes it essential to treat it promptly. Pregnancy among ladies with GT should be studied in multi-centers sitting to learn more about clinical courses and management.

Plasma-derived human factor X concentrate for the treatment of patients with hereditary factor X deficiency.

Hereditary factor X (FX) deficiency (HFXD) is an autosomal recessive rare bleeding disorder that leads to defects in the FX protein. Depending on the degree of deficiency, patients may be at risk of life-threatening bleeding episodes. Historical treatments for FX deficiency include prothrombin complex concentrates, which can increase the risk of thrombosis, and fresh frozen plasma, which can cause volume overload and transfusion reactions. Plasma-derived FX (pdFX), a single-factor, high-purity, high-potency human FX treatment, was approved in 2015 in the United States and in 2016 in Europe for on-demand treatment and prophylaxis of bleeding episodes and perioperative management of patients with HFXD. Five studies that examined the use of pdFX in patients with mild (plasma FX activity [FX:C] ≥5IU/dL), moderate (FX:C ≥1 and<5IU/dL), or severe (FX:C<1IU/dL) HFXD were reviewed: TEN01, TEN02 and TEN03 were prospective, open-label, multicentre, nonrandomised studies, and TEN05 and TEN06 were multicentre retrospective studies. When used as an on-demand treatment, pdFX was judged by investigators to be successful in treating 41/42 (97.6%), 2/3 (66.6%) and 79/79 (100%) bleeds in TEN01, TEN02 and TEN05, respectively. When used prophylactically, pdFX was judged 'excellent' for the prevention of bleeds in nine (100%) and eight (100%) patients in TEN02 and TEN05, respectively. Perioperative treatment and pharmacokinetics were also assessed. pdFX was safe and well tolerated. Together, these studies support the use of pdFX for on-demand treatment of bleeding, routine prophylaxis, and perioperative management of bleeding in patients with HFXD.

Overview of Ankle Arthropathy in Hereditary Hemochromatosis.

Hereditary hemochromatosis (HH) is an autosomal recessive bleeding disorder characterized by tissue overload of iron. Clinical systemic manifestations in HH include liver disease, cardiomyopathy, skin pigmentation, diabetes mellitus, erectile dysfunction, hypothyroidism, and arthropathy. Arthropathy with joint pain is frequently reported at diagnosis and mainly involves the metacarpophalangeal and ankle joints, and more rarely, the hip and knee. Symptoms in ankle joints are in most cases non-specific, and they can range from pain and swelling of the ankle to deformities and joint destruction. Furthermore, the main radiological signs do not differ from those of primary osteoarthritis (OA). Limited data are available in the literature regarding treatment; surgery seems to be the gold standard for ankle arthropathy in HH. Pharmacological treatments used to maintain iron homeostasis can also be undertaken to prevent the arthropathy, but conclusive data are not yet available. This review aimed to assess the ankle arthropathy in the context of HH, including all its aspects: epidemiology, physiopathology, clinical and imaging presentation, and all the treatments available to the current state of knowledge.

Utility of ACMG classification to support interpretation of molecular genetic test results in patients with factor VII deficiency.

The American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) have introduced an internationally shared framework for variant classification in genetic disorders. FVII deficiency is a rare inherited autosomal recessive bleeding disorder with sparse data concerning ACMG classification. To develop an approach which may improve the utility of molecular genetic test results, 129 patients with FVII deficiency were retrospectively assigned to six subgroups for exploratory analysis: F7 gene wildtype (group 1), ACMG 1 (benign variant) or ACMG 2 (likely benign variant), only (group 2), ACMG 3 (variant of uncertain significance) ± ACMG 1-2 heterozygous or not classified variant (group 3), ACMG 4 (likely pathogenic variant), or ACMG 5 (pathogenic variant) single heterozygous ± ACMG 1-3 single heterozygous (group 4), ACMG 4-5 homozygous or ≥2 ACMG 4-5 heterozygous or ≥1 ACMG 4-5 heterozygous plus either ACMG 1 c.1238G>A modifying variant homozygous or ≥2 ACMG 1-3 (group 5), FVII deficiency and another bleeding disorder (group 6). Eleven of 31 patients (35.5%) in group 5 had abnormal ISTH-BS (n = 7) and/or history of substitution with recombinant factor VIIa (n = 5) versus 4 of 80 patients (5.0%, n = 1 abnormal ISTH-BS, n = 3 substitution) in groups 1 (n = 2/22), 2 (n = 1/29), 3 (n = 0/9), and 4 (n = 1/20). Four of 18 patients (22.2%) with FVII deficiency and another bleeding disorder (group 6) had an abnormal ISTH-BS (n = 2) and/or history of substitution with recombinant factor VIIa (n = 3). Patients with a homozygous ACMG 4-5 variant or with specific combinations of heterozygous ACMG 4-5 ± ACMG 1-3 variants exhibited a high-risk bleeding phenotype in contrast to the remaining patients without another bleeding disorder. This result may serve as a basis to develop a genotype/phenotype prediction model in future studies.

Vaginal Delivery in a Primipara with Glanzmann Thrombasthenia

Vaginal Delivery in a Primipara with Glanzmann Thrombasthenia

Characterization of Novel &lt;i&gt;F5&lt;/i&gt; Intronic Variant Associated with Aberrant Splicing and Severe Factor V Deficiency

Congenital factor V deficiency is a rare autosomal recessive bleeding disorder, caused by defects in F5 gene and associated with bleeding manifestations of variable severity. In this study we report molecular and functional characterization of a novel F5 variant which causes aberrant splicing and significantly reduces protein expression in a patient with severe FV deficiency. We performed F5 mutation screening and functional study in a proband (FV:C 0.4%) with a history of gastrointestinal bleeding, post-traumatic bleeding, hematomas, ecchymoses, and discomfort in ankle joints since infancy. Sequencing revealed a novel homozygous F5 gene variant NC_000001.10:169519985GC (or NM_000130.5:c.1297 –8CG). Bioinformatics sequence analysis predicted that this variant would lead to the acceptor site loss of the intron 8/exon 9 junction. However mRN-A analysis identified, that it also activated the aberrant splice site located 7 nucleotides upstream of the normal one and was associated with the production of an anomalous F5 transcript with retention of seven nucleotides of intron 8 resulting in a premature stop codon. We revealed no traces of normal transcript in the patient. Our findings confirm that not only changes in canonical splicing dinucleotides could significantly disrupt the splicing sites and impair pre-mRNA processing.

Plasma Derived Factor X Concentrate Has Not Induced Inhibitor Development in the Clinical Setting

Background: Hereditary factor X deficiency (HFXD) is a rare autosomal recessive bleeding disorder caused by mutations in the F10 gene on chromosome 13. Historically, patients with HFXD were treated with nonspecific plasma formulations including fresh frozen plasma and prothrombin complex concentrates. Single factor concentrates are recommended by experts for treatment if available. Plasma derived factor X (pdFX) concentrate (Coagadex®, coagulation factor X, human, Bio Products Laboratory Ltd., Elstree, UK), has been granted a marketing license in both the US (2015) and EU (2016) for use in patients with HFXD. Inhibitor development with other factor concentrates has been a concern and is tracked in clinical trials and postmarketing use. Objectives: Data from clinical trials and postmarketing surveillance were gathered to understand the occurrence of FX inhibitor development following treatment with pdFX. The total number of patients and overall exposure is estimated to provide a denominator for inhibitor development. Methods: pdFX has been administered in two prospective clinical trials (TEN01 and TEN02) in the prophylactic and on-demand setting. Retrospective data were collected on 15 patients within the TEN05 protocol in the same setting. pdFX has been administered in the peri-operative setting in two studies (TEN03 and TEN06). All prospective clinical trials required inhibitor testing, at minimum once every 6 months, additionally following any significant bleeding, and at study completion. Postmarketing data are available from October 2015 to June 2022. Results: Sixteen patients, aged ≥12 years, participated in the TEN01 study and received a total of 468 infusions of pdFX. Of these, 242 infusions were administered on demand and 184 prophylactically. The mean number of infusions per patient was 29 (range 5-115). Patients received pdFX treatment for up to two years. In the TEN02 study, all nine patients were aged <9 years old and received pdFX prophylactically. Patients were treated for six months. 665 infusions were administered during the study with a mean of 74 infusions per patient (range 50-116). Peri-operative use of pdFX was assessed in eight patients undergoing ten procedures in the TEN03 and TEN06 studies. Duration of dosing ranged from 1 to 15 days. Two-thirds of patients in the TEN06 study were receiving pdFX prophylaxis prior to study entry. The TEN05 study was a retrospective data collection in fifteen patients who received pdFX on a compassionate use basis. 1366 infusions were administered during the data collection period with a mean of 91 infusions per patient (range 2-492). First approval was granted in the United States on October 20, 2015. Following the first approval, pdFX was approved in the 27 European Union Member States and the United Kingdom (UK) on March 16, 2016. It is estimated there have been over 26,000 infusions with pdFX and no inhibitors have been reported. Conclusion: To date, after over six years use in the postmarketing setting, there have been no reports of inhibitor development with pdFX.

Congenital factor V deficiency in Taiwan: identification of a novel variant p.Tyr1813 ∗ and two variants specific to East Asians.

Congenital coagulation factor V deficiency (FVD) is a rare, autosomal recessive bleeding disorder. We characterized the clinical presentations, laboratory features, and genetic alterations of Taiwanese patients with FVD. From 1983 to 2010, five women, one man, and one boy diagnosed with FVD were enrolled in this study. The factor V coagulant activity was determined using a one-stage prothrombin time-based test. The factor V antigen level was measured in an ELISA. Sanger sequencing was performed for genetic analyses of F5 , the gene responsible for the disease. One novel and de novo F5 genetic variant, p.Tyr1813 ∗ , was identified. Based on the presence of a premature termination codon with a resultant truncated factor V-protein lacking an intact light chain fragment, the variant is pathogenic. In addition, we identified seven variants previously found to cause FVD. Among them, p.Gly420Cys and p.Asp96His were repeatedly detected in five and four patients, respectively. Both variants are found to be specific to the East Asian populations. Various FVD-associated bleeding manifestations were observed, predominantly mucocutaneous bleeding and hypermenorrhea. All patients exhibited very low factor V coagulant activity (<1-2.5 IU/dl, reference range: 60-133 IU/dl). The factor V antigen level was less than 2% in six patients (reference range: 75-157%). The novel F5 genetic variant p.Tyr1813 ∗ and two distinct, East Asians-specific, recurrent variants p.Gly420Cys and p.Asp96His were identified among seven index patients with FVD in Taiwan. Our clinical and laboratory findings support the reported features of FVD.

Clinical phenotype and F7 gene genotype in 40 Tunisian patients with congenital factor VII deficiency.

Congenital factor VII (FVII) deficiency is an autosomal recessive bleeding disorder characterized by a weak phenotypic and genotypic correlation. This study aimed to determine the genetic alterations of 40 Tunisian patients and to evaluate their relationships with the collected clinical and biological data. Forty FVII-deficient Tunisian patients have been included in this study. First, diagnosis of the FVII deficiency was made on the basis of FVII coagulant activity (FVII:c) levels performed using the prothrombin time assay. Then, clinical and anamnesis data were set up and filed out from the regional registry of bleeding disorders and the medical file of each patient. Finally, genetic alterations were determined by direct sequencing of the coding regions, intron/exons boundaries of the F7 gene. Clinical heterogeneity was noticed, and the direct sequencing allowed the identification of 13 F7 gene mutations of which one was a novel mutation. The clinical manifestations are variably associated with FVII activity FVII:c levels. Lack of relations between severity of clinical manifestations and genotypes was observed; however, a relationship between the nonpathogeneous mutations and clinical phenotypes was noticed. A wide phenotypic inter-individual variability was detected, which suggests the presence of other extra-genetic components influencing the expressivity of the deficiency.

A review of the pharmacokinetics, efficacy and safety of high-purity factor X for the prophylactic treatment of hereditary factor X deficiency.

IntroductionHereditary factor X (FX) deficiency (FXD) is a rare autosomal recessive bleeding disorder. Plasma‐derived FX (pdFX) is a high‐purity FX concentrate approved in the United States and Europe for the treatment and prophylaxis of bleeding episodes and for peri‐operative management in patients with hereditary FXD (HFXD).AimTo review pharmacokinetic dosing, efficacy, and safety data for pdFX as routine prophylaxis for HFXD.MethodsSummary of the published pharmacokinetic and safety data from TEN01, TEN02, TEN05, and real‐world publications of pdFX for prophylaxis.ResultsPharmacokinetic modelling data from the phase 3 TEN01 study supported administration of pdFX 25 IU/kg twice weekly for routine prophylaxis in adolescents/adults (aged ≥12 years). Results from nine paediatric patients in the phase 3 TEN02 study and eight adolescents/adults (aged ≥12 years) in the retrospective data‐collection TEN05 study, along with real‐world evidence, showed that routine prophylaxis with pdFX ≈40 IU/kg twice weekly in patients aged <12 years and pdFX ≈25 IU/kg twice weekly in patients aged ≥12 years was effective in bleeding prevention.ConclusionspdFX was well tolerated in clinical studies, with no new safety signals identified during routine prophylactic use. Based on current evidence, it is recommended that routine prophylaxis with pdFX be initiated at 25 IU/kg twice weekly in adults/adolescents ≥12 years of age, and at a dosage of 40 IU/kg twice weekly in children <12 years of age. Thereafter, FX levels should be closely monitored, and dosages should be adjusted according to clinical response and to maintain trough levels ≥5 IU/dl.

A novel compound heterozygous variant linked to hematuria in a family with hereditary factor VII deficiency.

Hereditary factor VII deficiency (FVIID) is a rare congenital autosomal recessive bleeding disorder. In clinical manifestations, its onset is caused by variant of the F7 gene (NM_019616) with strong heterogeneity. We identified a family with hematuria caused by a novel F7 compound heterozygous variant and investigated the FVIID-dependent mechanism impacted by these variants. Coagulation factors in the proband were functionally verified. We located pathogenic variants in relevant genes using next-generation sequencing after target enrichment and verified them by Sanger sequencing. We examined the coagulation activity and secretion pattern of recombinant FVII variants expressed in cells and observed their location and stability by immunofluorescence. We found a missense variant c.1207G>A (p.Gly403Ser) and a frameshift variant c.154_155del (p.Arg53fs) in the F7 gene of the proband. FVII activity tests showed that the variants significantly decreased its presence in the cell culture supernatant. Moreover, the R53fs mutant lacked the FVII functional domain and had no detectable activity. Immunofluorescence indicated that the p.Gly403Ser variant was distributed to the cell membrane and cytoplasm, whereas the FVII R53fs variant was not detected. Deficient FVII protein function and severe coagulation disorder are the likely causes of hematuria and other bleeding symptoms in the proband. The newly discovered F7 gene variants enrich the spectrum of hereditary FVII deficiency and provide a new foundation for the diagnosis and treatment of this type of coagulation disorder.

Pediatric severe factor XI deficiency: A multicenter study.

Factor XI (FXI) deficiency is a rare autosomal recessive bleeding disorder. Only scarce publications address its clinical features in children. The increased prevalence of FXI deficiency in Israel enabled data collection for this large multicenter cohort study. Some hemostatic challenges may be unique or more common in children, such as bleeding in the neonatal period or trauma-related injury. The current study was designed to explore the potential impact of these differences in children with severe FXI deficiency. Medical files of all children with FXI level under 15% followed at five tertiary centers were evaluated. The retrieved data comprised demographic and clinical characteristics, including bleeding episodes, surgical interventions, treatment strategies, as well as laboratory features. Sixty children, whose median age at diagnosis was 4.2years and their median FXI level was 4%, were included. Three children experienced triggered intracranial hemorrhage (ICH) and two children had major bleeds. No bleeding complications occurred in surgeries in which hemostatic treatment consisting mostly of tranexamic acid or fresh frozen plasma was applied (n=45). In contrast, excessive bleeding was noted in 25% of surgical procedures performed without hemostatic preparation (p=.002). This study's findings confirm the generally favorable outcome of this rare bleeding disorder, with no spontaneous bleeds or cases of perinatal ICH. Nonetheless, proper diagnosis and adequate hemostasis in the surgical setting are imperative. Unlike previous studies in adults, our pediatric study suggests an association between the severity of FXI deficiency and bleeding tendency.

New αIIbβ3 variants in 28 Turkish Glanzmann patients; structural hypothesis for complex activation by residues variations in I-EGF domains

Glanzmann thrombasthenia (GT) is a rare autosomal recessive bleeding disorder characterized by impaired platelet aggregation due to defects in integrin αIIbβ3, a fibrinogen receptor. Platelet phenotypes and allelic variations in 28 Turkish GT patients are reported. Platelets αIIbβ3 expression was evaluated by flow cytometry. Sequence analyzes of ITGA2B and ITGB3 genes allowed identifying nine variants. Non-sense variation effect on αIIbβ3 expression was studied by using transfected cell lines. 3D molecular dynamics (MDs) simulations allowed characterizing structural alterations. Five new alleles were described. αIIb:p.Gly423Asp, p.Asp560Ala and p.Tyr784Cys substitutions impaired αIIbβ3 expression. The αIIb:p.Gly128Val substitution allowed normal expression; however, the corresponding NM_000419.3:c.476G>T variation would create a cryptic donor splicing site altering mRNA processing. The β3:p.Gly540Asp substitution allowed αIIbβ3 expression in HEK-293 cells but induced its constitutive activation likely by impairing αIIb and β3 legs interaction. The substitution alters the β3 I-EGF-3 domain flexibility as shown by MDs simulations. GT variations are mostly unique although the NM_000419.3:c.1752 + 2 T > C and NM_000212.2:c.1697 G > A variations identified in 4 and 8 families, respectively, might be a current cause of GT in Turkey. MD simulations suggested how some subtle structural variations in the β3 I-EGF domains might induce constitutive activation of αIIbβ3 without altering the global domain structure.

Generation and characterization of a human iPSC line SANi006-A from a Gray Platelet Syndrome patient

Induced pluripotent stem cells (iPSCs) were generated from erythroblasts (EBLs) obtained from a patient diagnosed with Gray Platelet Syndrome (GPS), caused by compound heterozygous NBEAL2 mutations (c.6568delT and c.7937T>C). GPS is an autosomal recessive bleeding disorder characterized by a lack of α-granules in platelets and progressive myelofibrosis. EBLs were reprogrammed with CytoTune-iPS 2.0 Sendai Reprogramming Kit, where the generated iPSCs showed normal karyotype, expression of pluripotency associated markers and in vitro spontaneous differentiation towards the three germ layers. The generated iPSCs can be used to study GPS pathophysiology and the basic functions of NBEAL2 protein in different cell types.

Interpretation of TEG Studies in Management of a Severe Glanzmann Thrombasthenia Patient

Glanzmann thrombasthenia (GT) is an autosomal recessive bleeding disorder which can result in mild to severe mucocutaneous bleeding. Patients with GT usually have normal platelet count, no clumping noted on peripheral blood smear and distinctly abnormal platelet dysfunction studies. NovoSeven®RT has been approved for treatment of this disease, however some patients have ongoing bleeding in spite of treatment with NovoSeven®RT and platelet transfusions. To add to the complexity of the treatment plan, sometimes the bleeding is retropharyngeal and children swallow blood making a timely assessment even more difficult. This case report summarizes additional tools used to control nasal bleeding and the use of TEG (Haemonetics Corporation) to assess therapeutic interventions.Our patient is a 6 year old female with GT who has behavioral issues and has lived in numerous foster homes. Severe nasal and retropharyngeal bleeds have resulted in repeated emergent transfusions. Part of the difficulty in her management has been her ability to swallow large amounts of blood without notifying her caregiver. She has had multiple blood transfusions and has had an allergic response to platelet plasma requiring washed platelet products with premedication (Benadryl/Solumedrol/Tylenol). Consideration for unrelated HLA donor stem cell transplant had been explored, however our patient's behavioral issues made her less likely to tolerate the transplant process. Her current treatment plan was developed to address local control, systemic control and to attempt to develop a means of assessing therapeutic interventions.Both nares and her retropharyngeal region were her primary bleeding sites. ENT evaluation identified numerous telangiectasias (AFP= 0.09). Repeated surveillance and cauterization followed by estrogen cream applied to the nasal mucousa twice daily greatly diminished the number of telangiectasias. Amicar® nasal spray (compounded as 10% nasal spray, used as 0.1 mL spray in each nostril), Zyrtec® nasal spray, nightly use of humidifier, normal saline nose gel, and cellulose gauze are medications used for local prevention and have been effective in preventing minor mouth and nose bleeds from becoming major bleeds.Systemic prevention regimen consisted of NovoSeven®RT prophylaxis BID 2 mg (90 mcg/kg/dose), Amicar® BID and behavioral support to avoid causing self induced trauma/bleeding. Since starting this regimen, all of her bleeds have been related to trauma or digital manipulation. NovoSeven®RT administered every 2 hours in addition to Amicar® TID and 1 to 2 units of washed pheresis platelets were utilized for treatment of active bleeding.Because of 2 prolonged bleeding episodes following transfusion with a single washed pheresis platelet unit, we attempted to find testing to assist us with evaluation.TEG Studies and InterpretationI. Table 1With a single dose of NovoSeven®RT our patient's RTEG value (time to produce thrombin) improved. However, the rate of clot development/propagation only improved to varying degrees (ANGLE TEG). The overall clot strength (MATEG) remained virtually unchanged.II. Table 2With a single washed pheresis unit of platelets, RTEG normalized and MATEG as well as the rate of propagation of the clot improved, however these values were not normal.With more than one washed pheresis platelet unit and NovoSeven®RT, TEG values almost normalized or returned to normal range, including clot strength represented by MATEG. These findings suggested the greater number of normal platelets transfused increased the likelihood of normal thrombin generation and clot formation. The loss of platelet product from washing likely resulted in decreased platelet numbers, perhaps decreasing the effectiveness of a single washed pheresis unit.We have utilized these findings to assist with the treatment of severe bleeds and to determine if more washed platelets would be beneficial when clinically the extent of bleeding cannot be determined in a short amount of time (i.e retropharyngeal bleeding). TEG is especially suited for rapid assessment and frequently used in Adult Trauma Centers. Treatment of a pediatric patient with significant bleeding and behavioral concerns requires a tool box of supportive measures. With local, systemic measures and use of TEG, we have been able to improve the safety of our GT patient, with decreases in major bleeds over the last year. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

A novel frameshift mutation in the ITGB3 gene leading to Glanzmann's thrombasthenia in a Saudi Arabian family

Glanzmann’s thrombasthenia (GT) is an autosomal recessive congenital bleeding disorder of platelet aggregation. Mutations in ITGA2B and ITGB3 genes result in quantitative and/or qualitative abnormalities of the glycoprotein receptor complex IIb/IIIa (integrin αIIbβ3), which in turn impairs platelet aggregation and lead to GT. In this study, whole genome single nucleotide polymorphism (SNP) genotyping as well as whole exome sequencing was performed in a large family segregating GT. Analysis of the genotypes localized the disease region to chromosome 17q21.2–q21.3. Filtration of whole exome data and candidate variants prioritization identified a pathogenic variant in the ITGB3 gene. The single nucleotide deletion variant (c.2113delC) in exon 13 of the ITGB3 gene is predicted to cause a frameshift and absence of vital C-terminal domains including the transmembrane helix and the cytoplasmic domain. Clinical variability of the bleeding phenotype in affected individuals with the same mutation suggests that other genetic and nongenetic factors are responsible for determining GT features.

Neutrophil specific granule and NETosis defects in gray platelet syndrome

AbstractGray platelet syndrome (GPS) is an autosomal recessive bleeding disorder characterized by a lack of α-granules in platelets and progressive myelofibrosis. Rare loss-of-function variants in neurobeachin-like 2 (NBEAL2), a member of the family of beige and Chédiak-Higashi (BEACH) genes, are causal of GPS. It is suggested that BEACH domain containing proteins are involved in fusion, fission, and trafficking of vesicles and granules. Studies in knockout mice suggest that NBEAL2 may control the formation and retention of granules in neutrophils. We found that neutrophils obtained from the peripheral blood from 13 patients with GPS have a normal distribution of azurophilic granules but show a deficiency of specific granules (SGs), as confirmed by immunoelectron microscopy and mass spectrometry proteomics analyses. CD34+ hematopoietic stem cells (HSCs) from patients with GPS differentiated into mature neutrophils also lacked NBEAL2 expression but showed similar SG protein expression as control cells. This is indicative of normal granulopoiesis in GPS and identifies NBEAL2 as a potentially important regulator of granule release. Patient neutrophil functions, including production of reactive oxygen species, chemotaxis, and killing of bacteria and fungi, were intact. NETosis was absent in circulating GPS neutrophils. Lack of NETosis is suggested to be independent of NBEAL2 expression but associated with SG defects instead, as indicated by comparison with HSC-derived neutrophils. Since patients with GPS do not excessively suffer from infections, the consequence of the reduced SG content and lack of NETosis for innate immunity remains to be explored.

Novel Compound Heterozygous Mutations in Two Families With Bernard–Soulier Syndrome

Background: Bernard–Soulier Syndrome (BSS) is a rare autosomal recessive bleeding disorder with large platelets and thrombocytopenia. It is caused by homozygous or compound heterozygous mutations in the GP1BA, GP1BB, or GP9 genes, which together encode the platelet surface receptor glycoprotein complex GPIb-IX-V.Objectives: We report two novel heterozygous mutations in the GP1BA and the GP9 genes, respectively.Patients/Methods: We analyzed the platelet glycoprotein expression by flow cytometry and screened the relevant genes for responsible mutations in two unrelated families.Results: Flow cytometric analyses revealed the absence of CD42a (GPIX) and CD42b (GPIb) on the platelets in the two affected siblings of family 1 and a significantly reduced expression of CD42b (GPIb) in the patient of family 2. In the two siblings, we identified a known frameshift (c.1601_1602delAT) and a novel nonsense mutation (c.1036C>T) in the GP1BA gene that abrogated the production of GP1bα. In the other patient, we found a novel missense mutation (c.112T>C) that was co-inherited with a common one (c.182A>G) in the GP9 gene, respectively. All analyzed heterozygous carriers were asymptomatic and had a normal GPIb-IX-V expression.Conclusions: The two novel GP1BA and GP9 mutations reported herein increment the number of causative genetic defects in BSS.