Case Of Hereditary Hemorrhagic Telangiectasia Research Articles

Uncommon presentation of a patient with hereditary haemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder. It is clinically characterised by telangiectasia, recurrent epistaxis, and visceral vascular lesions. We report a case of HHT without a significant family history. A 16-year-old girl presented with multiple episodes of bleeding, including uncommon sites, over a period of ten months. She denied a family history of bleeding. Her clinical examination was unremarkable. Investigations including basic and second-line coagulation tests were normal. Subsequently multiple telangiectasias in the right nasal septum and capillary dilatation in the bladder wall were detected. According to Curaçao diagnostic criteria, a diagnosis of HHT was made. As her bleeding was self-limiting, follow up was arranged to monitor complications.

A Case of Hereditary Hemorrhagic Telangiectasia With Gastrointestinal Tract Involvement

A Case of Hereditary Hemorrhagic Telangiectasia With Gastrointestinal Tract Involvement

An unusual diagnosis of small bowel bleeding: A case of hereditary hemorrhagic telangiectasia

In clinical practice, small bowel bleeding is primarily attributed to angiodysplasia associated with chronic kidney disease. Hereditary Hemorrhagic Telangiectasia (HHT) represents a relatively rare condition, which poses diagnostic challenges. Herein, we present the case of a 49-year-old male with chronic gastrointestinal bleeding. The diagnosis was established based on the patient’s medical history, imaging findings, and genetic testing.

Early Infantile Diagnosis of Hereditary Hemorrhagic Telangiectasia Complicated by Child Abuse

We report a rare case of hereditary hemorrhagic telangiectasia (HHT) in a 4-month-old female with findings of child abuse. She presented with poor feeding, vomiting, and irritability after a short fall from the bed. Initial evaluation found subdural hematomas (SDH), persistent hypoxia, failure to thrive (FTT), a frenulum tear, facial lacerations, and bruising. The patient was admitted and an extensive work-up led to the diagnosis of brain and pulmonary arteriovenous malformations (AVMs) and finally the diagnosis of HHT. The SDH, cutaneous injuries, and oral injury were highly suspicious for child abuse and were reported to Child Protective Services (CPS) and law enforcement for investigation simultaneous to the medical work-up. Her hospital course was complicated by progressive hypoxemia with radiographic evidence of several large pulmonary AVMs for which she underwent successful embolization. Her head injury was indeterminate for physical abuse in the setting of a medical condition pre-disposing to intracranial hemorrhage. A few weeks later, she was re-admitted with repeat abusive injuries in the form of femur fractures. This case demonstrates the unique diagnostic dilemma when two diagnoses are occurring simultaneously – HHT and child abuse – and showcases the importance of a detailed family history, genetic testing, strong multidisciplinary collaboration with a holistic approach and medically informed CPS systems to ensure accurate diagnoses and safe disposition.

Two Cases of Hereditary Hemorrhagic Telangiectasia with Severe Recurrent Epistaxis

Two Cases of Hereditary Hemorrhagic Telangiectasia with Severe Recurrent Epistaxis

Hepatic Vascular Variants in Hereditary Haemorrhagic Telangiectasia

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by vascular dysplasia. Hepatic vascular m alformations (VMs) range from small telangiectases to significant vascular shunting. Here we report two cases of HHT. Case 1 had diffuse ectasia of the hepatic artery along its intrahepatic and extrahepatic course with a hepatic arterial aneurysm. Case 2 presented with ileal and hepatic telangiectases. Knowledge of these vascular variants is indispensable for clinicians and radiologists in aiding diagnosis and surgical and interventional management. Keywords: Vascular Malformations; Hereditary Haemorrhagic Telangiectasia; Arteriovenous Malformation; Osler Weber Rendu.

S3000 A Missed Case of Hereditary Hemorrhagic Telangiectasia

S3000 A Missed Case of Hereditary Hemorrhagic Telangiectasia

Deficiency in hereditary hemorrhagic telangiectasia-associated Endoglin elicits hypoxia-driven heart failure in zebrafish.

Hereditary hemorrhagic telangiectasia (HHT) is a rare genetic disease caused by mutations affecting components of bone morphogenetic protein (BMP)/transforming growth factor-β (TGF-β) signaling in endothelial cells. This disorder is characterized by arteriovenous malformations that are prone to rupture, and the ensuing hemorrhages are responsible for iron-deficiency anemia. Along with activin receptor-like kinase (ALK1), mutations in endoglin are associated with the vast majority of HHT cases. In this study, we characterized the zebrafish endoglin locus and demonstrated that it produces two phylogenetically conserved protein isoforms. Functional analysis of a CRISPR/Cas9 zebrafish endoglin mutant revealed that Endoglin deficiency is lethal during the course from juvenile stage to adulthood. Endoglin-deficient zebrafish develop cardiomegaly, resulting in heart failure and hypochromic anemia, which both stem from chronic hypoxia. endoglin mutant zebrafish display structural alterations of the developing gills and underlying vascular network that coincide with hypoxia. Finally, phenylhydrazine treatment demonstrated that lowering hematocrit/blood viscosity alleviates heart failure and enhances the survival of Endoglin-deficient fish. Overall, our data link Endoglin deficiency to heart failure and establish zebrafish as a valuable HHT model.

Brain Abscess and Stroke in Children and Adults With Hereditary Hemorrhagic Telangiectasia: Analysis of a Large National Claims Database.

Hereditary hemorrhagic telangiectasia (HHT) is an inherited disease associated with pathogenic variants in transforming growth factor-β signaling pathway-related genes, resulting in abnormal vascular development in various organs. Brain arteriovenous malformations (AVMs) may lead to intracranial hemorrhage, and brain abscess or ischemic stroke may result from right to left shunting via pulmonary AVMs. We aimed to investigate the risk for these severe complications in both adults and children with HHT. We conducted a case-control study among participants aged 1-64 years in the MarketScan Commercial (2006-2019) and Multistate Medicaid Databases (2011-2019). We identified cases with HHT using International Classification of Diseases, Ninth/Tenth Revision, Clinical Modification (ICD-9/10) diagnosis codes (ICD-9-CM 448.0, ICD-10-CM I78.0). Control patients without HHT coding were frequency matched 10:1 to patients with HHT by age, duration of insurance enrollment, sex, and Medicaid status. Outcomes of interest (brain abscess, stroke, and intracranial/subarachnoid hemorrhage) were identified using the appropriate ICD-9/10 diagnosis codes. We calculated incidence and standardized rates of the various outcomes and compared rate ratios (RRs) between HHT cases and controls. A total of 5,796 patients with HHT, of whom 588 were children (age younger than 16 years), were matched with 57,960 controls. There was an increased incidence of brain abscesses in HHT cases compared with controls, with an RR of 35.6 (95% CI 15.4-82.5). No brain abscesses were recorded in children aged 15 years or younger. Hemorrhagic strokes/subarachnoid hemorrhages were more common in HHT cases, with an RR of 4.01 (95% CI 2.8-5.7) in adults and 60.2 (95% CI 7.2-500.4) in children. Ischemic strokes were also more common in cases, with an RR of 3.7 (95% CI, 3.0-4.5) in adults and 70.4 (95% CI 8.7-572.3) in children. We observed a much higher incidence of severe CNS vascular complications in patients with HHT, particularly in children. Although a higher incidence of brain abscesses was noted in adult patients with HHT, no brain abscesses were recorded in children, a result that may be considered when surveillance recommendations for this population are revisited.

Final observation of an extremely severe case of Osler-Weber-Rendu disease in teaching at the pregraduate and postgraduate stages of education and the use of current English-language Internet applications for doctors and patients

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome, Osler-Weber-Rendu disease, etc) is diagnosed clinically according to the so called Curacao criteria, if at least three of four of them are present: recurrent spontaneous epistaxis, mucocutaneous telangiectasias on characteristic locations, visceral vascular lesions and same disease in close relative. The described clinical case with dramatic outcome demonstrates an extremely severe course of Osler-Weber-Rendu disease complicated with recurrent massive epistaxis, long severe posthemorrhagic anemia requiring systemic red blood cell transfusions all of which became unfavorable background for the development of a fatal coronavirus disease. Demonstrations to students and interns of a rare clinical case of hereditary hemorrhagic telangiectasia with the use of actual English-language Internet sites help to improve the process of teaching general practice — family medicine at the pregraduate and postgraduate levels.

The Potential Role of MiRs-139-5p and -454-3p in Endoglin-Knockdown-Induced Angiogenic Dysfunction in HUVECs

Hereditary hemorrhagic telangiectasia (HHT) is a rare genetic disease characterized by aberrant angiogenesis and vascular malformations. Mutations in the transforming growth factor beta co-receptor, endoglin (ENG), account for approximately half of known HHT cases and cause abnormal angiogenic activity in endothelial cells (ECs). To date, how ENG deficiency contributes to EC dysfunction remains to be fully understood. MicroRNAs (miRNAs) regulate virtually every cellular process. We hypothesized that ENG depletion results in miRNA dysregulation that plays an important role in mediating EC dysfunction. Our goal was to test the hypothesis by identifying dysregulated miRNAs in ENG-knockdown human umbilical vein endothelial cells (HUVECs) and characterizing their potential role in EC function. We identified 32 potentially downregulated miRNAs in ENG-knockdown HUVECs with a TaqMan miRNA microarray. MiRs-139-5p and -454-3p were found to be significantly downregulated after RT-qPCR validation. While the inhibition of miR-139-5p or miR-454-3p had no effect on HUVEC viability, proliferation or apoptosis, angiogenic capacity was significantly compromised as determined by a tube formation assay. Most notably, the overexpression of miRs-139-5p and -454-3p rescued impaired tube formation in HUVECs with ENG knockdown. To our knowledge, we are the first to demonstrate miRNA alterations after the knockdown of ENG in HUVECs. Our results indicate a potential role of miRs-139-5p and -454-3p in ENG-deficiency-induced angiogenic dysfunction in ECs. Further study to examine the involvement of miRs-139-5p and -454-3p in HHT pathogenesis is warranted.

Recalcitrant Epistaxis: A case report of Hereditary Haemorrhagic Telangiectasia.

Hereditary haemorrhagic telangiectasia, also known as Rendu-Osler-Weber disease, is an autosomal dominant disorder of the fibrovascular tissue common in Western countries. It is characterized by the classical triad of mucocutaneous telangiectasia, arteriovenous malformations with recurrent epistaxis. Here we report a rare case of Hereditary haemorrhagic telangiectasia in a 66-year-old Indian male who presented with a history of recurrent epistaxis of forty years duration. The nasal telangiectasias were ablated under narrow band imaging guidance. The rarity of diagnosis was aided by clinical exome sequencing to confirm the disease.

Brain arteriovenous malformation in hereditary hemorrhagic telangiectasia: Recent advances in cellular and molecular mechanisms.

Hereditary hemorrhagic telangiectasia (HHT) is a genetic disorder characterized by vessel dilatation, such as telangiectasia in skin and mucosa and arteriovenous malformations (AVM) in internal organs such as the gastrointestinal tract, lungs, and brain. AVMs are fragile and tortuous vascular anomalies that directly connect arteries and veins, bypassing healthy capillaries. Mutations in transforming growth factor β (TGFβ) signaling pathway components, such as ENG (ENDOGLIN), ACVRL1 (ALK1), and SMAD4 (SMAD4) genes, account for most of HHT cases. 10-20% of HHT patients develop brain AVMs (bAVMs), which can lead to vessel wall rupture and intracranial hemorrhages. Though the main mutations are known, mechanisms leading to AVM formation are unclear, partially due to lack of animal models. Recent mouse models allowed significant advances in our understanding of AVMs. Endothelial-specific deletion of either Acvrl1, Eng or Smad4 is sufficient to induce AVMs, identifying endothelial cells (ECs) as primary targets of BMP signaling to promote vascular integrity. Loss of ALK1/ENG/SMAD4 signaling is associated with NOTCH signaling defects and abnormal arteriovenous EC differentiation. Moreover, cumulative evidence suggests that AVMs originate from venous ECs with defective flow-migration coupling and excessive proliferation. Mutant ECs show an increase of PI3K/AKT signaling and inhibitors of this signaling pathway rescue AVMs in HHT mouse models, revealing new therapeutic avenues. In this review, we will summarize recent advances and current knowledge of mechanisms controlling the pathogenesis of bAVMs, and discuss unresolved questions.

Pulmonary arterial hypertension in hereditary hemorrhagic telangiectasia associated with ACVRL1 mutation: a case report

IntroductionHereditary hemorrhagic telangiectasia is an autosomal dominant condition with an estimated prevalence of 1 in 5000. It is characterized by the presence of abnormalities of vascular structures, and may affect many organ systems, including the lungs, brain, spinal cord, gastrointestinal tract, and liver. A causative mutation is identified in approximately 97% of patients with definite hereditary hemorrhagic telangiectasia in one of three genes including a mutation in endoglin, a mutation in a locus mapped to chromosome 5, and an activin receptor-like kinase-1 (ACVRL1) mutation that is associated with an increased incidence of primary pulmonary hypertension. Pulmonary arterial hypertension is a rare (15–25 cases per million people) but severe vascular disorder. Heritable pulmonary arterial hypertension is associated with several gene mutations, with 75% having a mutation in the bone morphogenetic protein receptor 2 (BMPR2). However, the remaining 25% of patients have other associated genetic mutations including ACVLR1, which is also associated with hereditary hemorrhagic telangiectasia. Pulmonary arterial hypertension is a rare complication in patients with hereditary hemorrhagic telangiectasia (< 1% of the hereditary hemorrhagic telangiectasia population). We describe a case report with this rare occurrence.Case presentationA 70-year-old white/caucasian Irish male presented for screening for hereditary hemorrhagic telangiectasia due to a history of recurrent epistaxis (once/week) and a family history suggestive of pulmonary hypertension. Genetic testing confirmed an ACVRL1 mutation, while an echocardiogram and right heart catheterization confirmed pulmonary arterial hypertension. On examination, he had several mucocutaneous telangiectasia across his face. He was commenced on tadalafil and macitentan. However, this led to increased iron deficiency anemia and pedal edema. Selexipag was also added to his drug regime. He continues to require intermittent admissions for diuresis and blood transfusions.ConclusionThe association of hereditary hemorrhagic telangiectasia and pulmonary arterial hypertension is rare (< 1%). Here we describe a case of hereditary hemorrhagic telangiectasia complicated with pulmonary arterial hypertension as a result of an ACVRL1 mutation. We also describe the clinical challenges of treating these two conditions together, as treatment options for pulmonary arterial hypertension tend to worsen hereditary hemorrhagic telangiectasia symptoms.

Clinical and Economic Impact of Red Blood Cell Antigen Alloimmunization on Patients with Hereditary Hemorrhagic Telangiectasia

Hereditary Hemorrhagic Telangiectasia (HHT) is a rare autosomal dominant disorder characterized by the presence of arteriovenous malformations which lead to repeated bleeding episodes for which Red Blood Cell (RBC) transfusions may be required. Previous research has shown that this patient population presents with high rates of alloimmunization against RBC antigens (15.29%) (Zheng Transfusion. 2018;58(3):775-780). However, the impact of such complications on clinical and economic outcomes has not been assessed previously. The present study aims to quantify the impact of alloimmunization on clinical outcomes and healthcare costs among HHT patients in a hospital setting.A cross-sectional study of alloimmunized and non-alloimmunized patients using the Premier Hospital chargemaster dataset from January 2015 to June 2019 was performed. Alloimmunization was defined based on the presence of antiglobulin crossmatch and RBC antibody identification laboratory codes in patient medical records. In order to assess the accuracy of this method of identification, the alloimmunization rates among discharges for patients diagnosed with HHT and myelodysplastic syndrome (MDS) for 2018 were extrapolated to the whole country and compared to reports in the literature (Zheng Transfusion. 2018;58(3):775-780, Singhal Haematologica. 2017;102(12):2021-2029). Consistent results were shown, 16.8% vs 15.3% and 11.5% vs. 11% for the HHT and MDS discharges, respectively.Alloimmunized and non-alloimmunized groups were matched for sex, age, admission date, and visit type (outpatient vs. inpatient). Diagnosis of HHT was defined using ICD-10 code I78.0. Cost per discharge for outpatient and inpatient visits, hospital and intensive care unit (ICU) length of stays (LoS), and inpatient mortality were both cases and controls. Bivariate comparisons were performed assuming a two-tailed test of significance and α level of 0.05 and multivariable regression models adjusting for diagnosis-related groups (incidence ≥1%) were performed.A total of 783 alloimmunized HHT cases were matched to 6,744 non-alloimmunized controls. Mean (SD) age was 65.7 (10.9) years for the alloimmunized (cases) and 59.4 (16.3) for the non-alloimmunized (controls), and slightly more than half of the population included in both groups were females (53.0% and 54.0% for the alloimmunized and non-alloimmunized groups, respectively).Outpatient visits were more common than inpatient admissions in both groups (52.6% and 71.4% of cases and controls, respectively albeit inpatient admissions were less common in both control groups (47.4% vs. 28.6%). Most common diagnoses leading to inpatient admission in both groups were disorders of the circulatory system (16.1% and 8.0%, respectively), followed by blood disorders for the alloimmunized group (9.8%) and disorders of the digestive system for the non-alloimmunized group (3.6%).Alloimmunized HHT patients presented with 22% longer hospitalizations (6.1 vs 7.3 days; p=0.0001) and 54% longer ICU stays (4.7 vs 7.2 days; p=0.0146), as well as a 40% increased likelihood of being admitted to the ICU. Inpatient mortality was higher among the alloimmunized population although it did not reach statistical significance (Odds Ratio: 1.53 [0.79; 2.96]; p=0.2092). Overall 12 (3.23%) and 59 (3.1%) deaths were reported for the alloimmunized and non-alloimmunized patient population, respectively. Median costs per discharge were significantly higher both for inpatient ($1,461; p=0.0202) and outpatient ($377; p<0.0001) visits within the alloimmunized population (Table 1).Presence of alloantibodies was associated with significantly worse clinical outcomes, increased healthcare resource use and higher costs within HHT patients. The increased prevalence of alloimmunization within the HHT population is not yet fully understood, and this study was not designed to determine whether prophylactic antigen matching would prevent alloimmunization in the HHT population. Further studies assessing the use of preventive strategies such as prophylactic antigen matching to prevent alloimmunization and its clinical and economic consequences could help determine whether antigen negative RBC units should be preferentially distributed to HHT patients. [Display omitted] DisclosuresGehrie: Grifols SSNA: Consultancy, Honoraria. Viayna: Grifols S.A.: Current Employment. Blanchette: Grifols SSNA: Consultancy; Novo Nordisk Inc.: Current Employment. Meny: Grifols SSNA: Current Employment. Noumsi: Grifols SSNA: Current Employment. Huber: Grifols SSNA: Current Employment. Runken: Grifols SSNA: Current Employment.

Pathogenesis and therapy of arteriovenous malformations: A case report and narrative review.

Arteriovenous malformations (AVMs) are abnormal communications between arteries and veins that lack intervening capillary beds. They have been described in almost every organ in the body, emerging sporadically or as part of well-described syndromes. Hereditary hemorrhagic telangiectasia (HHT) is a rare, progressive, and lifelong disease characterized by AVMs and recurrent hemorrhaging. In the last 2 decades, significant advances have been made in understanding the pathogenesis of this condition. The accumulation of knowledge has led to a natural evolution of therapy, from open surgery to endovascular procedures, and now to a role for medications in certain AVMs. Here, we review a case of HHT and describe the most up-to-date clinical practice, including diagnosis of HHT, subtypes of HHT, and medical therapy.

A Case of Ruptured Cerebral Arteriovenous Malformation Associated with Hereditary Hemorrhagic Telangiectasia

Patients with hereditary hemorrhagic telangiectasia(HHT)are known to have high rates of cerebral arteriovenous malformations(AVMs). Compared to patients with sporadic AVMs, patients with HHT are less likely to present with ruptured AVMs. A 14-year-old male patient presented with headache that had lasted for 2 days. CT revealed an intracerebral hemorrhage in the right parietal lobe, and enhanced CT revealed an AVM in the upper part of the hematoma. The size of the nidus was 20 mm, and its feeders were the right superior internal parietal artery and a branch of the anterior cerebral artery. In addition, the AVM had no deep drainer. We also found another AVM in the right temporal lobe and identified telangiectasia of the nose using digital subtraction angiography. We suspected HHT and performed whole body CT, which revealed an arteriovenous fistula in the right lung and a hematoma-like lesion in the spleen. Thus, we diagnosed the patient with HHT. His ruptured AVM was removed electively. We report a case of HHT that presented as an intracerebral hemorrhage in a patient. Based on our case study findings, it is necessary to perform long-term follow-up not only for brain AVMs but also for visceral vascular malformations in such patients, as well as perform HHT screening for families. Although such cases are rare, some features of HHT must be considered to accurately diagnose suspected HHT.

Laser-Assisted Control of Epistaxis in Hereditary Hemorrhagic Telangiectasia: A Systematic Review.

Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu disease, causes recurrent mucous membrane hemorrhage, especially epistaxis. In this systematic review, we discuss the efficacies of the three most common laser photocoagulation treatments for HHT-related epistaxis. A systematic literature search was conducted in PubMed and MEDLINE from database inception to March 2019. Studies reporting epistaxis outcomes following argon, neodymium-doped yttrium aluminum garnet (Nd:YAG), and diode laser photocoagulation for HHT were included. χ2 and Barnard's exact tests were utilized to detect differences in reduced epistaxis frequency and intensity rates. Fifteen out of 157 published studies met our eligibility criteria, spanning a collective 362 patients. Argon, Nd:YAG, and diode laser therapy reduced epistaxis frequency in 90.4%, 88.9%, and 71.1% of patients, respectively, and reduced epistaxis intensity in 87.8%, 87.2%, and 71.1% of patients, respectively. Diode laser photocoagulation significantly underperformed in both outcome measurements when compared with argon (frequency: P = 0.005; intensity: P = 0.034) and Nd:YAG (frequency: P = 0.012; intensity: P = 0.041). There was no significant difference between argon and Nd:YAG in reducing HHT epistaxis frequency (P = 0.434) or intensity (P = 0.969). Categorizing HHT patients by clinical severity demonstrated a higher rate of improvement in the mild-moderate group compared with the severe group in both argon (P < 0.001) and Nd:YAG (P < 0.001) therapeutic methods. While no significant differences were found in rates of improved epistaxis outcomes between argon and Nd:YAG in mild-moderate HHT patients (frequency: P = 0.061; intensity: P = 0.061), Nd:YAG demonstrated greater rates of reduction in epistaxis frequency (P = 0.040) and intensity (P = 0.028) than argon among severe HHT patients. HHT is a lifelong disease, plaguing patients with debilitating epistaxis. Intranasal laser photocoagulation of telangiectasias using argon or Nd:YAG laser therapy can yield improved epistaxis outcomes compared with diode laser photocoagulation. In severe cases of HHT, Nd:YAG laser therapy provides greater improvements in epistaxis outcomes than argon photocoagulation. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Successful Treatment of Hereditary Hemorrhagic Telangiectasia With Octreotide

ABSTRACTHereditary hemorrhagic telangiectasia (HHT) is a disorder characterized by telangiectasias and arteriovenous malformations. We present a case report of a 74-year-old man diagnosed with HHT having a favorable response to a somatostatin analogue for treatment. This patient had been suffering from chronic anemia from recurrent gastrointestinal bleeding, requiring oral/intravenous iron replacement, frequent endoscopic ablations, and blood transfusions. Due to insufficient treatment, he was started on subcutaneous octreotide, with significant improvement as evidenced by a steady increase in the hemoglobin level, decreased endoscopic interventions, and decreased blood transfusions, making this the first case of HHT successfully treated with octreotide.

Assessing the Hereditary Hemorrhagic Telangiectasia Algorithms in a Community-Based Patient Population.

Hereditary hemorrhagic telangiectasia (HHT) is a rare, genetic, and underdiagnosed disease that causes vascular malformations throughout the body. Two specific combinations of International Classification of Diseases, Ninth Revision-Clinical Modification diagnosis codes, the "HHT Algorithms" (HHTAs), were developed previously from a derivation cohort to help identify undiagnosed HHT cases. To test these 2 algorithms, and a third, newly designed HHTA, in an independent population with available clinical records and thus identify people who might have undiagnosed HHT. The HHTAs were applied to the patient population of Kaiser Permanente Northern California. The HHTAs produced 3 groups (A, B, and C) using different combinations of diagnosis codes reflecting clinical manifestations of HHT. First, the number of Kaiser Permanente Northern California patients with each code was determined by database programming. Next, detailed chart review was performed, and patients with a Curaçao score of 2 or higher were considered to have possible HHT. Of 3,065,210 records queried, 163 patients met HHTA criteria. After chart review, the study identified 113 patients with possible undiagnosed HHT (Group A: n = 3, Group B: n = 3, Group C: n = 107). Employing the HHTAs in this community-based population resulted in a modest yield of patients with possible HHT. Further research is required to assess the utility of the HHTAs in identifying patients with actual HHT.