Epistaxis in children and adolescents with hereditary hemorrhagic telangiectasia: Epistaxis in Pediatric HHT

Case report: Novel homozygous ACVRL1 missense variant in a family with hereditary hemorrhagic telangiectasia and pulmonary arterial hypertension: findings suggest a hypomorphic allele

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder caused by pathogenic variants in genes within the transforming growth factor beta (TGF-β) signaling pathway, such as ACVRL1, leading to haploinsufficiency. Homozygous variants in HHT-related genes are exceptionally rare and have not been reported in ACVRL1-related HHT to date. We report the first known instance of a novel homozygous missense variant in the ACVRL1 gene (c.576C>G; p.Phe192Leu) identified in two siblings from a family of seven, in which three heterozygotes were also present. Comprehensive clinical evaluations revealed striking phenotypic differences between the homozygous and heterozygous family members. Both homozygous individuals exhibited early-onset pulmonary arterial hypertension and diffuse pulmonary arteriovenous malformations. One of them also demonstrated childhood-onset gastrointestinal bleeding-a manifestation unprecedented in HHT that typically has a late-adulthood onset. In contrast, the heterozygotes displayed either mild or equivocal features of HHT, supporting the classification of this variant as a hypomorphic allele. The novel missense variant is located within the intracellular glycine-serine (GS) domain of the protein, suggesting potential impacts on receptor regulation and downstream signaling. Although these findings expand the phenotypic spectrum of ACVRL1-related HHT, they remain limited to clinical observations. Experimental studies, including functional and molecular assays, are therefore essential to confirm the pathogenic impacts of this variant, validate its classification as a hypomorphic allele, and elucidate its effects on BMP-TGF-β signaling.

Specifications of the ACMG/AMP Variant Curation Guidelines for Hereditary Hemorrhagic Telangiectasia Genes-ENG and ACVRL1

The 2015 ACMG/AMP standards and guidelines for interpretation of sequence variants are widely used by laboratories, including for variant curation of the hereditary hemorrhagic telangiectasia (HHT) genes. However, the need for gene- and disease-specific modifications and specifications of these general guidelines to optimize and standardize variant classification was recognized at the time of publication. With this goal, the ClinGen HHT variant curation expert panel was formed. Here, we describe our recommended HHT-specific variant classification criteria and the outcomes from pilot testing of 30 variants of the ENG and ACVRL1 genes. Eight of the original ACMG/AMP rules were determined to not be applicable for ENG- or ACVRL1-related HHT or were previously recommended by ClinGen for removal, two rules were unmodified, and the remaining 18 rules were modified according to HHT specifications or previous ClinGen general recommendations. This study demonstrates the importance of HHT-specific criteria in the optimization and standardization of HHT variant classification and conflicting classification resolution.

Prevalence and Predictors of Hereditary Hemorrhagic Telangiectasia and Capillary-Malformation Arteriovenous Malformation Syndrome Among Children with Neurovascular Malformations

OBJECTIVE

To investigate the prevalence and predictors of hereditary hemorrhagic telangiectasia (HHT) and capillary-malformation arteriovenous malformation (CM-AVM) syndrome among children with no prior personal or family history of these diseases who presented with an arteriovenous shunt lesion.

STUDY DESIGN

A retrospective chart review was completed on patients aged 0 through 21 years with arteriovenous shunt lesions evaluated at our Cerebrovascular Center. Diagnosis of definite or suspected HHT or CM-AVM was based on clinical features and genetic testing. Associations between final diagnosis and type and number of lesions, epistaxis, telangiectasias, CM, and pulmonary AVMs were assessed.

RESULTS

Eighty-nine patients were included. Thirteen (14.6%) had definite HHT, 11 (12.4%) suspected HHT, and 4 (4.5%) definite CM-AVM. Having ≥2 episodes of epistaxis/year and ≥ 2 sites with telangiectasias were each associated with definite HHT (P < .001). Having ≥ 2 CM was associated with definite CM-AVM (P < .001). Pulmonary AVM was associated with increased odds of having definite HHT (OR = 6.3, 95% CI: 1.2-33.4). Multiple lesions (OR = 24.5, 95% CI: 4.5-134.8) and arteriovenous fistulas (OR = 6.2, 95% CI: 1.9-20.3) each increased the likelihood of having definite HHT or CM-AVM. Genetic testing was positive in 31% of patients tested.

CONCLUSIONS

We recommend that children with neurovascular shunt lesions be offered genetic testing and undergo further evaluation for HHT and CM-AVM. Awareness and early diagnosis of these conditions is a critical step toward improving long-term outcomes and preventing disease-associated complications.

Longitudinal Assessment of Curaçao Criteria in Children with Hereditary Hemorrhagic Telangiectasia

OBJECTIVE

To assess the utility of the Curaçao criteria by age over time in children with hereditary hemorrhagic telangiectasia (HHT).

STUDY DESIGN

This was a single-center, retrospective analysis of patients attending the HHT clinic at the Hospital for Sick Children (Toronto, Canada) between 2000 and 2019. The evaluation of the Curaçao criteria was completed during initial and follow-up visits. Screening for pulmonary and brain arteriovenous malformations was completed at 5 yearly intervals.

RESULTS

A total of 116 patients with genetic confirmation of HHT were included in the analysis. At initial screening at a median (IQR) age of 8.4 (2.8, 12.9) years, 41% met criteria for a definite clinical diagnosis (≥3 criteria). In children <6 years at presentation, only 23% fulfilled at least 3 criteria initially. In longitudinal follow-up, 63% reached a definite clinical diagnosis, with a median (IQR) follow-up duration of 5.2 (3.2, 7.9) years (P = .005). Specifically, more patients met the epistaxis and telangiectasia criteria at last visit compared with initial (79% vs 60%; P = .006; 47% vs 30%; P = .02) but not for the arteriovenous malformation criterion (59% vs 57%; P = .65).

CONCLUSIONS

In the pediatric population, most patients do not meet definite clinical criteria of HHT at initial presentation. Although the number of diagnostic criteria met increased over time, mainly due to new onset of epistaxis and telangiectasia, accuracy remained low during follow-up visits. Relying solely on clinical criteria may lead to underdiagnosis of HHT in children.

Age Distribution of Epistaxis in Outpatient Pediatric Patients

Objectives: Little is known about the prevalence of epistaxis in children. Existing reports focus on hospitalized children or those presenting to an emergency department. To better understand pediatric epistaxis in clinical practice, we sought out a searchable, representative outpatient database and examined the incidence of epistaxis in children of different ages. Methods: A cross-sectional analysis of data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) from the years 2007 to 2011 was performed. The NHAMCS is a Centers for Disease Control and Prevention-curated national sample of data from visits to non-federally employed office-based physicians and health centers. We queried the NHAMCS to determine the cumulative incidence of epistaxis in children of different age groups. The International Classification of Diseases Ninth Revision code 784.7 was chosen to identify epistaxis. Comparisons of rates were performed using the chi-squared test. A P-value of <.05 was considered statistically significant. Results: In total, 55,435,691 children [27,816,237 (50.2%) males, 55,435,691 (77.2%) white] were included. The overall cumulative incidence rate of epistaxis was 2.4/1000 children. Children in the 3- to 5-year range had the highest cumulative incidence of epistaxis (5.0/1000), followed by those in the 6 to 8 (3.0/1000), 9 to 11 (2.0/1000), 0 to 2 (1.9/1000), 12 to 14 (1.6/1000), and 15 to 17 (0.5/1000) year ranges (P < .001). Conclusion: Pediatric epistaxis is common in the office setting (2.4 per 1000 children)-and well above emergency department estimates (1.7 per 1000 people). Children between the ages of 3 to 5 years have the highest cumulative incidence. Epistaxis is sufficiently unusual in infants and the late teens that alternative causes for nasal bleeding should be included in the differential diagnosis.

Hereditary Hemorrhagic Telangiectasia in Pediatric Age: Focus on Genetics and Diagnosis

Hereditary Hemorrhagic Telangiectasia (HHT) or Rendu-Osler-Weber Syndrome (ROW) is an autosomal dominant vascular disease, with an estimated prevalence of 1:5000. Genes associated with HHT are ACVRL1, ENG, SMAD4, and GDF2, all encoding for proteins involved in the TGFβ/BMPs signaling pathway. The clinical diagnosis of HHT is made according to the "Curaçao Criteria," based on the main features of the disease: recurrent and spontaneous epistaxis, muco-cutaneous telangiectases, arteriovenous malformations in the lungs, liver, and brain, and familiarity. Since the clinical signs of HHT can be misinterpreted, and the primary symptom of HHT, epistaxis, is common in the general population, the disease is underdiagnosed. Although HHT exhibits a complete penetrance after the age of 40, young subjects may also present symptoms of the disease and are at risk of severe complications. Here we review the literature reporting data from clinical, diagnostic, and molecular studies on the HHT pediatric population.

A Rare Case of Upper Gastrointestinal Bleeding: Osler-Weber-Rendu Syndrome

Osler-Weber-Rendu disease, also known as hereditary hemorrhagic telangiectasia (HHT), is a rare, autosomal dominant condition that affects approximately 1 in 5000 patients causing abnormal blood vessel formation. HHT patients have mucocutaneous telangiectasias and arteriovenous malformations in various organs. The most prominent symptom of HHT is epistaxis, which, together with gastrointestinal bleeding, may cause iron deficiency anemia. This study is a case report of a 62-year-old patient who was admitted to the Department of Gastroenterology due to acute upper gastrointestinal bleeding and a history of recurrent epistaxis and melena for 4 days, which was confirmed in digital rectal examination. Urgent upper gastrointestinal endoscopy revealed active bleeding from multiple angioectatic spots with bright-looking salmon-colored patches in the antrum and the body suggestive of HHT. The bleeding from two angioectatic spots was stopped by argon plasma coagulation, and four clips were placed to provide good hemostasis. The patient was treated with a proton pomp inhibitor infusion and iron infusion. She was discharged with no signs of GI bleeding, normalized iron levels and a diagnosis of HHT. She was referred to further genetic testing, including evaluation of first-degree relatives. She also had performed unenhanced thin-cut computed tomography (CT) with angiography to exclude the presence of pulmonary arteriovenous malformations (PAVMs). Due to the fact that the patient did not manifest any other HHT-related symptoms and that the instrumental screening discloses no silent AVMs in other organs, the "watch-and-wait strategy" was applied. Although, Osler-Weber-Rendu syndrome is widely described in the medical literature, effective treatment of gastrointestinal telangiectasias is not always available and still lacks standardization to date, which makes the management of gastroenterological involvement still a challenging issue.

Imaging to intervention: a review of what the Interventionalist needs to Know about Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a disorder that affects 1 in 5000-10,000 people worldwide and can result in devastating complications such as cerebral abscess, stroke, massive hemorrhage, and even death. HHT is an autosomal dominant disorder that leads to the formation of abnormal communication between the arteries and veins with a resultant spectrum of vascular anomalies. The disorder affects many organ systems and thus requires a dedicated multidisciplinary approach. Interventional radiologists are vital members of this team providing expertise not only in disease management, but in complex embolotherapy, helping to maintain the health of these patients. This article reviews clinical manifestations, screening guidelines, diagnostic criteria, and endovascular management of HHT.

Nasal Endoscopy in the Clinical Diagnosis of Hereditary Hemorrhagic Telangiectasia

OBJECTIVES

To evaluate the role of nasal endoscopy for early clinical diagnosis of hereditary hemorrhagic telangiectasia (HHT) in children and to investigate the characteristics of epistaxis and mucocutaneous telangiectases in our pediatric population.

STUDY DESIGN

From May 2016 to December 2019, a cross-sectional observational study was conducted, recruiting children aged 2-18 years with a parent affected by HHT. To identify the Curaçao criteria, all children underwent collection of clinical history, mucocutaneous examination, and nasal endoscopy. The clinical data were then compared with the genetic data acquired subsequently.

RESULTS

Seventy children (median age, 10.8 years) were included. All underwent nasal endoscopy without complications. Forty-six children were positive by genetic testing; of these, 26 % had skin and oral telangiectases and 91 % had nasal telangiectases. The diagnostic sensitivity of the Curaçao criteria increased from 28 % (95 % CI, 16%-43 %) to 85 % (95 % CI, 71%-94 %; P < .0001) when the nasal telangiectases were included.

CONCLUSIONS

The magnified and complete endoscopic view of the nasal cavities proved useful in increasing the diagnostic sensitivity of the Curaçao criteria. Such an examination turned out to be feasible and safe. For this reason, we believe that nasal endoscopy should be included in the diagnostic assessment of pediatric patients with suspected HHT.

Epistaxis limits the performed activities of daily living in proportion to its severity: a cross-sectional survey among patients with hereditary haemorrhagic telangiectasia

Background: We examined the severity of epistaxis in patients with hereditary haemorrhagic telangiectasia (HHT) and its relationship with the performed activities of daily living. Methodology: This cross-sectional survey included 36 patients with HHT in Japan. An anonymous questionnaire survey was conducted regarding the severity of epistaxis, the measures adopted to prevent epistaxis, and the limitations in the performed activities of daily living. The latter was assessed using a visual analogue scale (VAS). The correlation between epistaxis severity and the VAS score was analysed using Spearman’s rank correlation coefficient. Results: Of the 36 participants surveyed, 94.4% had >1 episode of epistaxis/week. The mean epistaxis severity score (ESS) was 4.3 (range, 0.9–8.4). Limitations in daily life, going out (within a day), meeting with others, eating with others, and going on overnight trips were positively correlated with the ESS. To prevent nosebleeds, 44.4% and 41.7% of the participants used medications and avoided drying their nasal cavities, respectively. Conclusions: Epistaxis impacted the daily life of patients with HHT in proportion to its severity. Nonetheless, less than half of the patients used medications or took precautions. Hence, further educational activities should be considered for medical professionals and patients.

Sclerotherapy Versus Cautery/Laser Treatment for Epistaxis in Hereditary Hemorrhagic Telangiectasia

OBJECTIVES/HYPOTHESIS

Surgical interventions for epistaxis management in hereditary hemorrhagic telangiectasia (HHT) demonstrate short-term success and require repeated procedures for disease control. Although electrocautery and/or laser photocoagulation (C ± L) are most frequently performed, sodium tetradecyl sclerotherapy (STS) is emerging as a promising newer treatment. We hypothesized that in a 24-month time period, STS would require fewer treatments than C ± L to maintain epistaxis severity within the mild range.

STUDY DESIGN

Retrospective study.

METHODS

We retrospectively assessed 67 patients with HHT with moderate and severe epistaxis that were treated periodically with C ± L (34 patients) versus STS (33 patients). The primary outcome was the number of procedures needed to maintain the epistaxis severity score (ESS) as mild. Secondary outcomes assessed for differences in postoperative complications, hemoglobin levels, iron stores, hematologic support, and quality-of-life (QoL) scores.

RESULTS

To maintain ESS in the mild range, 1.6 STS procedures (range, 1-4) were performed versus 3.6 C ± L procedures (range, 1-8) (P = .003). Significant postoperative differences included reduction in nasal crusting (3% vs. 32%, P = .001), foul odor (3% vs. 35%, P < .001), and septal perforation (3% vs. 29%, P = .006) after STS. There were no significant differences between the two treatments in hemoglobin levels, iron stores, hematologic support, or QoL scores.

CONCLUSION

STS is able to attain satisfactory epistaxis control with significantly fewer procedures and lower postoperative complications than C ± L. STS should be considered as the initial surgical intervention for epistaxis in patients with HHT.

LEVEL OF EVIDENCE

IV Laryngoscope, 2021.

Genotype-Phenotype Correlations in Children with HHT

Hereditary hemorrhagic telangiectasia (HHT), a rare autosomal dominant disease mostly caused by mutations in three known genes (ENG, ACVRL1, and SMAD4), is characterized by the development of vascular malformations (VMs). Patients with HHT may present with mucocutaneous telangiectasia, as well as organ arteriovenous malformations (AVMs) of the central nervous system, lungs, and liver. Genotype-phenotype correlations have been well described in adults with HHT. We aimed to investigate genotype-phenotype correlations among pediatric HHT patients. Demographic, clinical, and genetic data were collected and analyzed in 205 children enrolled in the multicenter Brain Vascular Malformation Consortium HHT Project. A chi-square test was used to determine the association between phenotypic presentations and genotype. Among 205 patients (age range: 0-18 years; mean: 11 years), ENG mutation was associated with the presence of pulmonary AVMs (p < 0.001) and brain VM (p < 0.001). The presence of a combined phenotype-defined as both pulmonary AVMs and brain VMs-was also associated with ENG mutation. Gastrointestinal bleeding was rare (4.4%), but was associated with SMAD4 genotype (p < 0.001). We conclude that genotype-phenotype correlations among pediatric HHT patients are similar to those described among adults. Specifically, pediatric patients with ENG mutation have a greater prevalence of pulmonary AVMs, brain VMs, and a combined phenotype.

Homozygous GDF2-Related Hereditary Hemorrhagic Telangiectasia in a Chinese Family

Hereditary hemorrhagic telangiectasia (HHT) can be clinically diagnosed, but children often lack characteristic features. We report a family with homozygous growth differentiation factor 2 (GDF2)-related HHT diagnosed by genetic testing. A boy aged 5 years and 2 months presented with isolated hypoxemia. He was the product of a consanguineous marriage; his parents were second cousins. Physical examination revealed cyanosis of nail beds and clubbed fingers. Pulse oxygen saturation was 84% to 89%. Lung function, contrast-enhanced lung computed tomography, and noncontrast echocardiography were normal. A pulmonary perfusion scan revealed radioactivity in the brain and bilateral kidney, suggesting the existence of a intrapulmonary shunt. Whole-exome sequencing revealed a homozygous variant [c.1060_1062delinsAG (p.Tyr354ArgfsTer15)] in GDF2, which was found to be inherited from his heterozygous parents. At the age of 8 years, he developed epistaxis, and an angiogram revealed diffuse pulmonary arteriovenous malformations. At the age of 9 years, he was treated with sirolimus, and his condition improved significantly. However, his now 7-year-old sister with the same homozygous variant currently has no symptoms. Physical examinations revealed 1 pinpoint-sized telangiectasia on the chest of his mother and a vascular lesion on the forehead of his sister. Additionally, the patient's father and great-uncle had a history of mild to moderate epistaxis. Mutation in GDF2 is a rare cause of HHT. Ours is the first report of homozygous GDF2-related HHT; in addition, this variant has not been reported previously. In our report, we also confirm variable expressivity, even with the same pathogenic variant in GDF2-related HHT.

Phenotype of CM-AVM2 caused by variants in EPHB4: how much overlap with hereditary hemorrhagic telangiectasia (HHT)?

PURPOSE

EPHB4 variants were recently reported to cause capillary malformation-arteriovenous malformation 2 (CM-AVM2). CM-AVM2 mimics RASA1-related CM-AVM1 and hereditary hemorrhagic telangiectasia (HHT), as clinical features include capillary malformations (CMs), telangiectasia, and arteriovenous malformations (AVMs). Epistaxis, another clinical feature that overlaps with HHT, was reported in several cases. Based on the clinical overlap of CM-AVM2 and HHT, we hypothesized that patients considered clinically suspicious for HHT with no variant detected in an HHT gene (ENG, ACVRL1, or SMAD4) may have an EPHB4 variant.

METHODS

Exome sequencing or a next-generation sequencing panel including EPHB4 was performed on individuals with previously negative molecular genetic testing for the HHT genes and/or RASA1.

RESULTS

An EPHB4 variant was identified in ten unrelated cases. Seven cases had a pathogenic EPHB4 variant, including one with mosaicism. Three cases had an EPHB4 variant of uncertain significance. The majority had epistaxis (6/10 cases) and telangiectasia (8/10 cases), as well as CMs. Two of ten cases had a central nervous system AVM.

CONCLUSIONS

Our results emphasize the importance of considering CM-AVM2 as part of the clinical differential for HHT and other vascular malformation syndromes. Yet, these cases highlight significant differences in the cutaneous presentations of CM-AVM2 versus HHT.