Endoscopic evaluation of gastrointestinal tract in patients with hereditary hemorrhagic telangiectasia and correlation with their genotypes. Genet Med. 2014;16:3-10. [PMID: 23722869 DOI: 10.1038/gim.2013.62]

Pathogenic Variant Frequencies in Hereditary Haemorrhagic Telangiectasia Support Clinical Evidence of Protection from Myocardial Infarction

Hereditary haemorrhagic telangiectasia (HHT) is a vascular dysplasia inherited as an autosomal dominant trait, due to a single heterozygous loss-of-function variant, usually in ACVRL1 (encoding activin receptor-like kinase 1 [ALK1]), ENG (encoding endoglin [CD105]), or SMAD4. In a consecutive single-centre series of 37 positive clinical genetic tests performed in 2021-2023, a skewed distribution pattern was noted, with 30 of 32 variants reported only once, but ACVRL1 c.1231C>T (p.Arg411Trp) identified as the disease-causal gene in five different HHT families. In the same centre's non-overlapping 1992-2020 series where 110/134 (82.1%) HHT-causal variants were reported only once, ACVRL1 c.1231C>T (p.Arg411Trp) was identified in nine further families. In a 14-country, four-continent HHT Mutation Database where 181/250 (72.4%) HHT-causal variants were reported only once, ACVRL1 c.1231C>T (p.Arg411Trp) was reported by 12 different laboratories, the adjacent ACVRL1 c.1232G>A (p.Arg411Gln) by 14, and ACVRL1 c.1120C>T (p.Arg374Trp) by 18. Unlike the majority of HHT-causal ACVRL1 variants, these encode ALK1 protein that reaches the endothelial cell surface but fails to signal. Six variants of this type were present in the three series and were reported 6.8-25.5 (mean 8.9) times more frequently than the other ACVRL1 missense variants (all p-values < 0.0039). Noting lower rates of myocardial infarction reported in HHT, we explore potential mechanisms, including a selective paradigm relevant to ALK1's role in the initiating event of atherosclerosis, where a plausible dominant negative effect of these specific variants can be proposed. In conclusion, there is an ~9-fold excess of kinase-inactive, cell surface-expressed ACVRL1/ALK1 pathogenic missense variants in HHT. The findings support further examination of differential clinical and cellular phenotypes by HHT causal gene molecular subtypes.

Gastrointestinal bleeding in patients with hereditary hemorrhagic telangiectasia: Long-term results of endoscopic treatment

Background and study aims This longitudinal prospective study evaluated the long-term outcome of endoscopic treatment of gastrointestinal bleeding in hereditary hemorrhagic telangiectases (HHT), its safety and outcome predictors. Patients and methods Consecutive patients with HHT and either anemia disproportionate to epistaxis or overt gastrointestinal bleeding received endoscopic treatment of gastrointestinal telangiectases with argon plasma coagulation (APC). Hemoglobin levels and transfusion requirements were evaluated before and after treatment. Treatment effectiveness was classified as: 1) complete: hemoglobin level during the follow-up ≥9 g/dL; 2) complete with recurrence: hemoglobin ≥9 g/dL for at least 12 months with subsequent drop to <9 g/dL; or 3) absent: no improvement of hemoglobin level. Adverse events (AEs) were classified as mild, moderate, severe or fatal. Correlations were searched between treatment outcome and demographic/genetic characteristics, number, size and site of telangiectases, and hepatic arterio-venous malformations grade. Results Forty-seven patients with HHT were enrolled. At median follow-up of 134 months (range 20-243 months), 41 of 47 patients showed treatment response (complete or with recurrence) after one (14/47) or more (27/47) endoscopic treatments. Median hemoglobin levels were 7.0 g/dL and 11.9 g/dL at baseline and at the end of follow-up, respectively. Transfusion requirement decreased from 22.8 to 7.3 red cell unit/year. A higher baseline number of telangiectases was associated with a lower chance of response ( P =0.008). Only one severe AE (0.4%, jejunal perforation) was recorded. Conclusions Endoscopic treatment of gastrointestinal teleangiectases for gastrointestinal bleeding in patients with HHT is effective in the long term and safe.

Hepatic Vascular Variants in Hereditary Haemorrhagic Telangiectasia: Imaging findings

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by vascular dysplasia. Hepatic vascular malformations (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.

Antiplatelet and anticoagulant therapies in hereditary hemorrhagic telangiectasia: A large French cohort study (RETROPLACOTEL)

BACKGROUND

It is unclear whether hereditary hemorrhagic telangiectasia (HHT) patients can tolerate antithrombotic therapies (AT) including antiplatelet (AP) and/or anticoagulant (AC) agents.

OBJECTIVES

Primary endpoint was tolerance to AT in HHT. Secondary endpoints were to identify factors associated with major bleeding events (MBE) and premature discontinuation of AT.

METHODS

Retrospective multicenter study in French national HHT Registry patients exposed to AT.

RESULTS

We included 126 patients with 180 courses of AT. Median follow-up was 24 [11-52] months. Mean age was 65.6 ± 13.1 years. The first 3 months of AT exposure had an increased risk of hospitalization for hemorrhage (p < 0.001) and transfusions (p < 0.001). MBE (n = 63) occurred more frequently in the first 3 months of AT exposure (p < 0.001). Premature discontinuation of AT occurred in 61 cases. Rate of premature discontinuation was 29 % under both AP and AT therapy but significantly higher under dual AP therapy (n = 4/7, 57 % p = 0.008). Risk factors for MBE were: age ≥ 60 years (HR 2.34 [1.12;4.87], p = 0.023), prior hospitalization in the 3 months before starting AT for hemorrhage (HR 3.59 [1.93;6.66], p < 0.001) or transfusion (HR 3.15 [1.61;6.18], p = 0.001), previous history of gastro-intestinal bleeding (HR 2.71 [1.57;4.65], p < 0.001) or MBE (HR 4.62 [2.68;7.98], p < 0.001). Frequency of MBE did not differ between groups except for a higher risk in the dual AP group (HR 3.92 [1.37;11.22], p = 0.011).

CONCLUSION

Tolerance of AC or AP therapy was similar in HHT population but not dual AP therapy. We identified risk factors for MBE occurrence or premature discontinuation under AT.

Hereditary Hemorrhagic Telangiectasia in a Young Adult: Gastrointestinal Arteriovenous Malformations as a Presenting Feature

Hereditary hemorrhagic telangiectasia (HHT) is characterized by the presence of multiple arteriovenous malformations (AVM) in which arteries and venules are connected directly without intervening capillaries. The primary clinical presentation is spontaneous and recurrent nosebleeds (epistaxis), typically starting around 12. Telangiectases, which are small arteriovenous malformations, are commonly found in mucocutaneous areas and gastrointestinal (GI) mucosa. The presentation of epistaxis precedes the occurrence of telangiectases. Larger AVMs most commonly affect the lungs, liver, or brain, and complications from bleeding or shunting can be potentially life-threatening. Here, we discuss the case of a 44-year-old man who presented to the emergency department with a chief complaint of fatigue for three weeks associated with shortness of breath. His eventual labs revealed severe anemia with a hemoglobin of 4.4 g/dL. He denied any history of symptoms of GI bleeding. Computed tomography of the abdomen was done which did not reveal any intra-abdominal bleeding, hematoma, or abnormality. Further history revealed a recent diagnosis of HHT in his mother through genetic testing. During the stay, he also developed spontaneous epistaxis which was treated with topical vasoconstrictors by the ear, nose, and throat (ENT) physician. Given the high likelihood of HHT, he underwent luminal evaluation. Upper and lower endoscopies of the gut revealed multiple AVMs. A diagnosis of HHT was established as he fulfilled the criteria required for the diagnosis of HHT. It is rare for individuals with HHT to experience GI bleeding before the age of 50, making this case unique.

Long-term use of somatostatin analogs for chronic gastrointestinal bleeding in hereditary hemorrhagic telangiectasia

Background

Chronic bleeding due to gastrointestinal (GI) involvement in patients with hemorrhagic hereditary telangiectasia (HHT) can provoke severe anemia with high red blood cells (RBC) transfusion requirements. However, the evidence about how to deal with these patients is scarce. We aimed to assess the long-term efficacy and safety of somatostatin analogs (SA) for anemia management in HHT patients with GI involvement.

Methods

This is a prospective observational study including patients with HHT and GI involvement attended at a referral center. SA were considered for those patients with chronic anemia. Anemia-related variables were compared in patients receiving SA before and during treatment. Patients receiving SA were divided into responders (patients with minimal hemoglobin levels improvement >10 g/L and maintaining hemoglobin levels ≥80 g/L during treatment), and non-responders. Adverse effects during follow-up were collected.

Results

Among 119 HHT patients with GI involvement, 67 (56.3%) received SA. These patients showed lower minimal hemoglobin levels (73 [60-87] vs. 99 [70.2-122.5], p < 0.001), and more RBC transfusion requirements (61.2% vs. 38.5%, p = 0.014) than patients without SA therapy. Median treatment period was 20.9 ± 15.2 months. During treatment, there was a statistically significant improvement in minimum hemoglobin levels (94.7 ± 29.8 g/L vs. 74.7 ± 19.7, p < 0.001) and a reduction of patients with minimal hemoglobin levels <80 g/L (39 vs. 61%, p = 0.007) and RBC transfusions requirement (33.9% vs. 59.3%, p < 0.001). Sixteen (23.9%) patients showed mild adverse effects, mostly diarrhea or abdominal pain, leading to treatment discontinuation in 12 (17.9%) patients. Fifty-nine patients were eligible for efficacy assessment and 32 (54.2%) of them were considered responders. Age was associated with non-responder patients, OR 95% CI; 1.070 (1.014-1.130), p = 0.015.

Conclusion

SA can be considered a long-term effective and safe option for anemia management in HHT patients with GI bleeding. Older age is associated with poorer response.

[Hereditary hemorrhagic telangiectasia]

Hereditary hemorrhagic telangiectasia, also known as Rendu-Osler - Weber disease, is a rare, autosomal dominant vascular disease, with prevalence of 1/5,000. The condition is characterized by muco-cutaneous telangiectasias, which are responsible for a hemorrhagic syndrome of variable severity, as well as arteriovenous malformations (AVMs) appearing in the lungs, the liver, and the nervous system. They can be the source of shunts, which may be associated with high morbidity (neurological ischemic stroke, brain abscess, high-output heart failure, biliary ischemia…). It is therefore crucial to establish a clinical diagnosis using the Curaçao criteria or molecular diagnosis based on genetic analysis of the ENG, ACVRL1, SMAD4 and GDF2 genes. In most cases, multidisciplinary management allows patients to have normal life expectancy. Advances in interventional radiology and better understanding of the pathophysiology of angiogenesis have resulted in improved therapeutic management. Anti-angiogenic treatments, such as bevacizumab (BVZ, an anti-VEGF antibody), have proven to be effective in cases involving bleeding complications and severe liver damage with cardiac repercussions. Other anti-angiogenic agents are currently being investigated, including tyrosine kinase inhibitors.

Hereditary Hemorrhagic Telangiectasia: Genetics, Pathophysiology, Diagnosis, and Management

Hereditary hemorrhagic telangiectasia is an inherited disease related to an alteration in angiogenesis, manifesting as cutaneous telangiectasias and epistaxis. As complications, it presents vascular malformations in organs such as the lung, liver, digestive tract, and brain. Currently, diagnosis can be made using the Curaçao criteria or by identifying the affected gene. In recent years, there has been an advance in the understanding of the pathophysiology of the disease, which has allowed the use of new therapeutic strategies to improve the quality of life of patients. This article reviews some of the main and most current evidence on the pathophysiology, clinical manifestations, diagnostic approach, screening for complications, and therapeutic options, both pharmacological and surgical.

Systemic Antiangiogenic Therapies for Bleeding in Hereditary Hemorrhagic Telangiectasia: A Practical, Evidence-Based Guide for Clinicians

Management of bleeding in hereditary hemorrhagic telangiectasia (HHT), the second most common hereditary bleeding disorder in the world, is currently undergoing a paradigm shift. Disease-modifying antiangiogenic therapies capable of achieving durable hemostasis via inducing telangiectasia regression have emerged as a highly effective and safe modality to treat epistaxis and gastrointestinal bleeding in HHT. While evidence to date is incomplete and additional studies are ongoing, patients presently in need are being treated with antiangiogenic agents off-label. Intravenous bevacizumab, oral pazopanib, and oral thalidomide are the three targeted primary angiogenesis inhibitors, with multiple studies describing both reassuring safety and impressive effectiveness in the treatment of moderate-to-severe HHT-associated bleeding. However, at present there is a paucity of guidance in the literature, including the published HHT guidelines, addressing the practical aspects of antiangiogenic therapy for HHT in clinical practice. This review article and practical evidence-based guide aims to fill this unaddressed need, synthesizing published data on the use of antiangiogenic agents in HHT, relevant data for their use outside of HHT, and expert guidance where evidence is lacking. After a brief review of principles of bleeding therapy in HHT, guidance on hematologic support with iron and blood products, and alternatives to antiangiogenic therapy, this article examines each of the aforementioned antiangiogenic agents in detail, including patient selection, initiation, monitoring, toxicity management, and discontinuation. With proper, educated use of antiangiogenic therapies in HHT, patients with even the most severe bleeding manifestations can achieve durable hemostasis with minimal side-effects, dramatically improving health-related quality of life and potentially altering the disease course.

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.

Clinical characteristics and prognosis analysis of idiopathic and hereditary pulmonary hypertension patients with ACVRL1 gene mutations

Pulmonary arterial hypertension is a kind of heart and lung vascular disease with low incidence and poor prognosis. Genetic variants are the important factors of pulmonary arterial hypertension. The mutations of activin receptor-like kinase-1 (ACVRL1) could cause pulmonary arteriole obstruction and occlusion in pulmonary arterial hypertension patients. The ACVRL1 gene mutation and clinical characteristics of Chinese idiopathic or hereditary pulmonary hypertension (IPAH/HPAH) patients are still unclear. This study aimed to retrospectively study the mutation characteristics of ACVRL1 gene in Chinese IPAH/HPAH patients and its effect on clinical prognosis. We analyzed the clinical, functional, hemodynamic and mutation characteristics of 12 IPAH/HPAH patients with ACVRL1 mutations and compared with 94 IPAH/HPAH patients (27 patients carried bone morphogenetic protein receptor type 2 (BMPR2) mutations and 67 without mutations). All ACVRL1 mutations of 12 patients were single nucleotide missense mutations. The ratio of male to female in 12 patients was 1:1. The diagnosis age of ACVRL1 mutation patients was younger than that of BMPR2 mutation patients (13.6 ± 11.3 years vs. 16.0 ± 12.9 years) but higher than that of patients without mutations (13.6 ± 11.3 years vs. 8.8 ± 8.5 years, p = 0.006). IPAH/HPAH patients with ACVRL1 mutation have rapid disease progresses, high overall mortality rate (approximately 50%) and no response to the acute pulmonary vasodilation test. In conclusion, this is the first study to analyze the ACVRL1 gene mutation and clinical characteristics of Chinese IPAH/HPAH patients. It is beneficial to screen ACVRL1 gene mutation for IPAH/HPAH patients to facilitate genetic counseling and early prevention and treatment.

Hereditary hemorrhagic telangiectasia (HHT): a practical guide to management

Hereditary hemorrhagic telangiectasia (HHT), the second most common inherited bleeding disorder, is associated with the development of malformed blood vessels. Abnormal blood vessels may be small and cutaneous or mucosal (telangiectasia), with frequent complications of bleeding, or large and visceral (arteriovenous malformations [AVMs]), with additional risks that can lead to significant morbidity and even mortality. HHT can present in many different ways and can be difficult to recognize, particularly in younger patients in the absence of a known family history of disease or epistaxis, its most common manifestation. HHT is commonly diagnosed using the established Curaçao clinical criteria, which include (1) family history, (2) recurrent epistaxis, (3) telangiectasia, and (4) visceral AVMs. Fulfillment of 3 or more criteria provides a definite diagnosis of HHT, whereas 2 criteria constitute a possible diagnosis of HHT. However, these criteria are insufficient in children to rule out disease due to the age-dependent development of some of these criteria. Genetic testing, when positive, can provide definitive diagnosis of HHT in all age groups. Clinical course is often complicated by significant epistaxis and/or gastrointestinal bleeding, leading to anemia in half of adult patients with HHT. The management paradigm has recently shifted from surgical approaches to medical treatments aimed at control of chronic bleeding, such as antifibrinolytic and antiangiogenic agents, combined with aggressive iron replacement with intravenous iron. Guidelines for management of HHT, including screening and treatment, were determined by expert consensus and originally published in 2009 with updates and new guidelines in 2020.

Mutational and clinical spectrum of Japanese patients with hereditary hemorrhagic telangiectasia

Background

Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited vascular disorder characterized by recurrent epistaxis, skin/mucocutaneous telangiectasia, and organ/visceral arteriovenous malformations (AVM). HHT is mostly caused by mutations either in the ENG or ACVRL1 genes, and there are regional differences in the breakdown of causative genes. The clinical presentation is also variable between populations suggesting the influence of environmental or genetic backgrounds. In this study, we report the largest series of mutational and clinical analyses for East Asians.

Methods

Using DNAs derived from peripheral blood leukocytes of 281 Japanese HHT patients from 150 families, all exons and exon–intron boundaries of the ENG, ACVRL1, and SMAD4 genes were sequenced either by Sanger sequencing or by the next-generation sequencing. Deletions/amplifications were analyzed by the multiplex ligation-dependent probe amplification analyses. Clinical information was obtained by chart review.

Results

In total, 80 and 59 pathogenic/likely pathogenic variants were identified in the ENG and ACVRL1 genes, respectively. No pathogenic variants were identified in the SMAD4 gene. In the ENG gene, the majority (60/80) of the pathogenic variants were private mutations unique to a single family, and the variants were widely distributed without any distinct hot spots. In the ACVRL1 gene, the variants were more commonly found in exons 5–10 which encompasses the serine/threonine kinase domain. Of these, 25/59 variants were unique to a single family while those in exons 8–10 tended to be shared by multiple (2–7) families. Pulmonary and cerebral AVMs were more commonly found in ENG-HHT (69.1 vs. 14.4%, 34.0 vs. 5.2%) while hepatic AVM was more common in ACVRL1-HHT (31.5 vs. 73.2%). Notable differences include an increased incidence of cerebral (34.0% in ENG-HHT and 5.2% in ACVRL1-HHT), spinal (2.5% in ENG-HHT and 1.0% in ACVL1-HHT), and gastric AVM (13.0% in ENG-HHT, 26.8% in ACVRL1-HHT) in our cohort. Intrafamilial phenotypic heterogeneity not related to the age of examination was observed in 71.4% and 24.1% of ENG- and ACVRL1-HHT, respectively.

Conclusions

In a large Japanese cohort, ENG-HHT was 1.35 times more common than ACVRL1-HHT. The phenotypic presentations were similar to the previous reports although the cerebral, spinal, and gastric AVMs were more common.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-01139-y.

Hereditary haemorrhagic telangiectasia: an overview from an ear, nose and throat perspective

Patients with hereditary haemorrhagic telangiectasia can present with a multitude of symptoms caused by telangiectasia and arteriovenous malformations in the nose, brain, gastrointestinal tract, liver and spinal cord. Clinicians should be aware of the potential diagnosis of hereditary haemorrhagic telangiectasia and how to manage these patients both in the acute and chronic setting. Identifying these patients and optimising their management can help reverse the reduced life expectancy back to that of the normal population. The management of these patients is complex and often requires a multidisciplinary approach, with difficult discussions to be had around screening for arteriovenous malformations and genetic testing. The stepwise management ladder can be used in both the medical and surgical strategies; there are multiple pharmacological and surgical options available, all with their own side effects and risks. Patient education is key to help informed decision making. This article outlines the clinical characteristics of the disease and management options available.

Hereditary hemorrhagic telangiectasia: systemic therapies, guidelines, and an evolving standard of care

Hereditary hemorrhagic telangiectasia (HHT) management is evolving because of the emergence and development of antiangiogenic therapies to eliminate bleeding telangiectasias and achieve hemostasis. This progress is reflected in recent clinical recommendations published in the Second International Guidelines for the Diagnosis and Treatment of HHT, in which systemic therapies including antiangiogenics and antifibrinolytics are now recommended as standard treatment options for bleeding. This review highlights the new recommendations especially relevant to hematologists in managing bleeding, anticoagulation, and anemia in patients with HHT.

Management of Refractory Gastrointestinal Bleeding in Hereditary Hemorrhagic Telangiectasia with Bevacizumab

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder resulting in vascular malformations of several organs including the pulmonary, cerebral, and gastrointestinal systems. One sequela is recurrent gastrointestinal (GI) bleeding. Bevacizumab (Bev) is emerging as an effective treatment of recurrent gastrointestinal bleeding in HHT. Bev is a recombinant monoclonal antibody that inhibits vascular endothelial growth factor (VEGF), an integral part of angiogenesis.

Prevalence of Angiodysplasia Detected in Upper Gastrointestinal Endoscopic Examinations

Background This study was performed to examine the prevalence of asymptomatic angiodysplasia detected in upper gastrointestinal endoscopic examinations and of hereditary hemorrhagic telangiectasia (HHT) suspected cases. Methodology The study participants were 5,034 individuals (3,206 males, 1,828 females; mean age 53.5 ± 9.8 years) who underwent an upper gastrointestinal endoscopic examination as part of a medical check-up. The presence of angiodysplasia was examined endoscopically from the pharynx to duodenal second portion. HHT suspected cases were diagnosed based on the presence of both upper gastrointestinal angiodysplasia and recurrent nasal bleeding episodes occurring in the subject as well as a first-degree relative. Results Angiodysplasia was endoscopically detected in 494 (9.8%) of the 5,061 subjects. Those with angiodysplasia lesions in the pharynx, larynx, esophagus, stomach, and duodenum numbered 44, 4, 155, 322, and 12, respectively. None had symptoms of upper gastrointestinal bleeding or severe anemia. Subjects with angiodysplasia showed significant male predominance and were significantly older than those without. A total of 11 (0.2%) were diagnosed as HHT suspected cases by the presence of upper gastrointestinal angiodysplasia and recurrent epistaxis episodes from childhood in the subject as well as a first-degree relative. Conclusions Asymptomatic angiodysplasia was detected in 9.8% of the subjects who underwent screening upper gastrointestinal endoscopic examinations.

Arteriovenous Malformations in the Setting of Osler-Weber-Rendu: What the Radiologist Needs to Know

Osler-Weber-Rendu, also known as Hereditary Hemorrhagic Telangiectasia, is an autosomal dominant disease with phenotypic manifestations that include pulmonary, cerebrospinal, hepatic, and other visceral arteriovenous malformations (AVMs). Pulmonary AVMs can result in hypoxemia, hemoptysis, or stroke due to paradoxical embolism. The mainstay of treatment is transcatheter embolization. Central nervous system and abdominal visceral AVMs contribute to morbidity of the disease. Radiologists should be familiar with the imaging manifestations and treatment algorithm of AVMs in Osler-Weber-Rendu to effectively guide patient care.

Management of Gastrointestinal Bleeding in Rendu-Osler Disease

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT, or Rendu-Osler-Weber disease) is a rare inherited syndrome, characterized by artero-venous malformations (AVMs or telangiectasia) with autosomal dominant transmission. AVMs can occur in any organ of the body but most commonly it occurs in the nose, pulmonary, hepatic and cerebral circulations. In patients with HHT, we report teleangectasia of mucosa of the gastrointestinal tract.

METHODS

Research and online content related to HHT online activity is reviewed, and DOC writing excerpts are used to illustrate key themes.

RESULTS

Patients with HHT have a high rate of complications related to bleeding; of them gastrointestinal bleeding accounts for 10.8%. Several therapies, both medical and endoscopic, were utilized to reduce the need for transfusions and hospitalization.

CONCLUSION

A combination of medical and endoscopic therapy is probably the best option.

Predictors of mortality in patients with hereditary hemorrhagic telangiectasia

BACKGROUND

Retrospective questionnaire and healthcare administrative data suggest reduced life expectancy in untreated hereditary hemorrhagic telangiectasia (HHT). Prospective data suggests similar mortality, to the general population, in Denmark's centre-treated HHT patients. However, clinical phenotypes vary widely in HHT, likely affecting mortality. We aimed to measure predictors of mortality among centre-treated HHT patients. HHT patients were recruited at 14 HHT centres of the Brain Vascular Malformation Consortium (BVMC) since 2010 and followed annually. Vital status, organ vascular malformations (VMs) and clinical symptoms data were collected at baseline and during follow-up (N = 1286). We tested whether organ VMs, HHT symptoms and HHT genes were associated with increased mortality using Cox regression analysis, adjusting for patient age, sex, and smoking status.

RESULTS

59 deaths occurred over average follow-up time of 3.4 years (max 8.6 years). A history of anemia was associated with increased mortality (HR = 2.93, 95% CI 1.37-6.26, p = 0.006), as were gastro-intestinal (GI) bleeding (HR = 2.63, 95% CI 1.46-4.74, p = 0.001), and symptomatic liver VMs (HR = 2.10, 95% CI 1.15-3.84, p = 0.015). Brain VMs and pulmonary arteriovenous malformations (AVMs) were not associated with mortality (p > 0.05). Patients with SMAD4 mutation had significantly higher mortality (HR = 18.36, 95% CI 5.60-60.20, p < 0.001) compared to patients with ACVRL1 or ENG mutation, but this estimate is imprecise given the rarity of SMAD4 patients (n = 33, 4 deaths).

CONCLUSIONS

Chronic GI bleeding, anemia and symptomatic liver VMs are associated with increased mortality in HHT patients, independent of age, and in keeping with the limited treatment options for these aspects of HHT. Conversely, mortality does not appear to be associated with pulmonary AVMs or brain VMs, for which patients are routinely screened and treated preventatively at HHT Centres. This demonstrates the need for development of new therapies to treat chronic anemia, GI bleeding, and symptomatic liver VMs in order to reduce mortality among HHT patients.

Second International Guidelines for the Diagnosis and Management of Hereditary Hemorrhagic Telangiectasia

DESCRIPTION

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease with an estimated prevalence of 1 in 5000 that is characterized by the presence of vascular malformations (VMs). These result in chronic bleeding, acute hemorrhage, and complications from shunting through VMs. The goal of the Second International HHT Guidelines process was to develop evidence-based consensus guidelines for the management and prevention of HHT-related symptoms and complications.

METHODS

The guidelines were developed using the AGREE II (Appraisal of Guidelines for Research and Evaluation II) framework and GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology. The guidelines expert panel included expert physicians (clinical and genetic) in HHT from 15 countries, guidelines methodologists, health care workers, health care administrators, patient advocacy representatives, and persons with HHT. During the preconference process, the expert panel generated clinically relevant questions in 6 priority topic areas. A systematic literature search was done in June 2019, and articles meeting a priori criteria were included to generate evidence tables, which were used as the basis for recommendation development. The expert panel subsequently convened during a guidelines conference to conduct a structured consensus process, during which recommendations reaching at least 80% consensus were discussed and approved.

RECOMMENDATIONS

The expert panel generated and approved 6 new recommendations for each of the following 6 priority topic areas: epistaxis, gastrointestinal bleeding, anemia and iron deficiency, liver VMs, pediatric care, and pregnancy and delivery (36 total). The recommendations highlight new evidence in existing topics from the first International HHT Guidelines and provide guidance in 3 new areas: anemia, pediatrics, and pregnancy and delivery. These recommendations should facilitate implementation of key components of HHT care into clinical practice.

National recommendations of the French Genetics and Cancer Group - Unicancer on the modalities of multi-genes panel analyses in hereditary predispositions to tumors of the digestive tract

In case of suspected hereditary predisposition to digestive cancers, next-generation sequencing can analyze simultaneously several genes associated with an increased risk of developing these tumors. Thus, "Gastro Intestinal" (GI) gene panels are commonly used in French molecular genetic laboratories. Lack of international recommendations led to disparities in the composition of these panels and in the management of patients. To harmonize practices, the Genetics and Cancer Group (GGC)-Unicancer set up a working group who carried out a review of the literature for 31 genes of interest in this context and established a list of genes for which the estimated risks associated with pathogenic variant seemed sufficiently reliable and high for clinical use. Pancreatic cancer susceptibility genes have been excluded. This expertise defined a panel of 14 genes of confirmed clinical interest and relevant for genetic counseling: APC, BMPR1A, CDH1, EPCAM, MLH1, MSH2, MSH6, MUTYH, PMS2, POLD1, POLE, PTEN, SMAD4 and STK11. The reasons for the exclusion of the others 23 genes have been discussed. The paucity of estimates of the associated tumor risks led to the exclusion of genes, in particular CTNNA1, MSH3 and NTHL1, despite their implication in the molecular pathways involved in the pathophysiology of GI cancers. A regular update of the literature is planned to up-grade this panel of genes in case of new data on candidate genes. Genetic and epidemiological studies and international collaborations are needed to better estimate the risks associated with the pathogenic variants of these genes either selected or not in the current panel.

Overexpression of Activin Receptor-Like Kinase 1 in Endothelial Cells Suppresses Development of Arteriovenous Malformations in Mouse Models of Hereditary Hemorrhagic Telangiectasia

RATIONALE

Hereditary hemorrhagic telangiectasia (HHT) is a genetic disease caused by mutations in ENG, ALK1, or SMAD4. Since proteins from all 3 HHT genes are components of signal transduction of TGF-β (transforming growth factor β) family members, it has been hypothesized that HHT is a disease caused by defects in the ENG-ALK1-SMAD4 linear signaling. However, in vivo evidence supporting this hypothesis is scarce.

OBJECTIVE

We tested this hypothesis and investigated the therapeutic effects and potential risks of induced-ALK1 or -ENG overexpression (OE) for HHT.

METHODS AND RESULTS

We generated a novel mouse allele (ROSA26^Alk1) in which HA (human influenza hemagglutinin)-tagged ALK1 and bicistronic eGFP expression are induced by Cre activity. We examined whether ALK1-OE using the ROSA26^Alk1 allele could suppress the development of arteriovenous malformations (AVMs) in wounded adult skin and developing retinas of Alk1- and Eng-inducible knockout (iKO) mice. We also used a similar approach to investigate whether ENG-OE could rescue AVMs. Biochemical and immunofluorescence analyses confirmed the Cre-dependent OE of the ALK1-HA transgene. We could not detect any pathological signs in ALK1-OE mice up to 3 months after induction. ALK1-OE prevented the development of retinal AVMs and wound-induced skin AVMs in Eng-iKO as well as Alk1-iKO mice. ALK1-OE normalized expression of SMAD and NOTCH target genes in ENG-deficient endothelial cells (ECs) and restored the effect of BMP9 (bone morphogenetic protein 9) on suppression of phosphor-AKT levels in these endothelial cells. On the other hand, ENG-OE could not inhibit the AVM development in Alk1-iKO models.

CONCLUSIONS

These data support the notion that ENG and ALK1 form a linear signaling pathway for the formation of a proper arteriovenous network during angiogenesis. We suggest that ALK1 OE or activation can be an effective therapeutic strategy for HHT. Further research is required to study whether this therapy could be translated into treatment for humans.

Decreased Colonic Activin Receptor-Like Kinase 1 Disrupts Epithelial Barrier Integrity in Patients With Crohn's Disease

BACKGROUND & AIMS

Intestinal epithelial cell (IEC) barrier dysfunction is critical to the development of Crohn's disease (CD). However, the mechanism is understudied. We recently reported increased microRNA-31-5p (miR-31-5p) expression in colonic IECs of CD patients, but downstream targets and functional consequences are unknown.

METHODS

microRNA-31-5p target genes were identified by integrative analysis of RNA- and small RNA-sequencing data from colonic mucosa and confirmed by quantitative polymerase chain reaction in colonic IECs. Functional characterization of activin receptor-like kinase 1 (ACVRL1 or ALK1) in IECs was performed ex vivo using 2-dimensional cultured human primary colonic IECs. The impact of altered colonic ALK1 signaling in CD for the risk of surgery and endoscopic relapse was evaluated by a multivariate regression analysis and a Kaplan-Meier estimator.

RESULTS

ALK1 was identified as a target of miR-31-5p in colonic IECs of CD patients and confirmed using a 3'-untranslated region reporter assay. Activation of ALK1 restricted the proliferation of colonic IECs in a 5-ethynyl-2-deoxyuridine proliferation assay and down-regulated the expression of stemness-related genes. Activated ALK1 signaling increased colonic IEC differentiation toward colonocytes. Down-regulated ALK1 signaling was associated with increased stemness and decreased colonocyte-specific marker expression in colonic IECs of CD patients compared with healthy controls. Activation of ALK1 enhanced epithelial barrier integrity in a transepithelial electrical resistance permeability assay. Lower colonic ALK1 expression was identified as an independent risk factor for surgery and was associated with a higher risk of endoscopic relapse in CD patients.

CONCLUSIONS

Decreased colonic ALK1 disrupted colonic IEC barrier integrity and was associated with poor clinical outcomes in CD patients.

Current HHT genetic overview in Spain and its phenotypic correlation: data from RiHHTa registry

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disease with autosomal dominant inheritance. Disease-causing variants in endoglin (ENG) and activin A receptor type II-like 1 (ACVRL1) genes are detected in more than 90% of cases submitted to molecular diagnosis.

METHODS

We used data from the RiHHTa (Computerized Registry of Hereditary Hemorrhagic Telangiectasia) registry to describe genetic variants and to assess their genotype-phenotype correlation among HHT patients in Spain.

RESULTS

By May 2019, 215 patients were included in the RiHHTa registry with a mean age of 52.5 ± 16.5 years and 136 (63.3%) were women. Definitive HHT diagnosis defined by the Curaçao criteria were met by 172 (80%) patients. Among 113 patients with genetic test, 77 (68.1%) showed a genetic variant in ACVRL1 and 36 (31.8%) in ENG gene. The identified genetic variants in ACVRL1 and ENG genes and their clinical significance are provided. ACVRL1 mutations were more frequently nonsense (50%) while ENG mutations were more frequently, frameshift (39.1%). ENG patients were significantly younger at diagnosis (36.9 vs 45.7 years) and had pulmonary arteriovenous malformations (AVMs) (71.4% vs 24.4%) and cerebral AVMs (17.6% vs 2%) more often than patients with ACVRL1 variants. Patients with ACVRL1 variants had a higher cardiac index (2.62 vs 3.46), higher levels of hepatic functional blood tests, and anemia (28.5% vs 56.7%) more often than ENG patients.

CONCLUSIONS

ACVRL1 variants are more frequent than ENG in Spain. ACVRL1 patients developed symptomatic liver disease and anemia more often than ENG patients. Compared to ACVRL1, those with ENG variants are younger at diagnosis and show pulmonary and cerebral AVMs more frequently.

A case report of unexplained jejunal telangiectasia complicated with bleeding

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Jejunal telangiectasia with bleeding is relatively rare in clinic.

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The main clinical manifestation of small intestinal telangiectasia is hematochezia.

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This disease is prone to recurrent bleeding.

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There is a lack of specific and effective diagnostic methods in clinical.

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We gave some experience and suggestions in the process of surgical treatment.

Introduction

Small intestinal telangiectasia is a clinically rare disease, which is mainly characterized by gastrointestinal bleeding. There is a lack of specific and effective diagnostic methods in clinical practice due to its unknown etiology and difficult localization, it is often difficult to find the location of the lesion even through observation, touch, endoscope or intestinal incision.

Case presentation

A 39-year-old female patient, who had black stool twice without obvious inducement 3 days ago, and came to our hospital for treatment and was hospitalized with gastrointestinal bleeding. the main manifestation of this patient was repeated black stool, sometimes dark red. Initially, we considered other diseases of the digestive tract (gastric ulcers, duodenal ulcers and intestinal tumors). However, no abnormalities were found by CT, gastroscopy and enteroscopy. Later, we considered that there was a greater possibility of intestinal vascular disease, and then blood clots was found in the upper and middle segment of the jejunum through capsule endoscopy, but no bleeding site was found. Therefore, we decided to open the abdomen for further intraoperative enteroscopy exploration, finally found the bleeding point, and then stopped the bleeding by suture. Later, through further follow-up, no rebleeding was found in the patient.

Conclusion

Jejunal telangiectasia with bleeding is a very rare intestinal vascular disease, which is difficult to identify and diagnose clinically. Therefore, the possibility of this disease should be considered in patients with negative results through some examinations such as gastroscopy, enteroscopy, gastrointestinal barium meal radiography, etc. In order to treat in time and prevent bleeding

Gastrointestinal Bleeding in Patients with Hereditary Hemorrhagic Telangiectasia: Risk Factors and Endoscopic Findings

Background: We aimed to describe risk factors for gastrointestinal (GI) bleeding and endoscopic findings in patients with hereditary hemorrhagic telangiectasia (HHT). Methods: This is a prospective study from a referral HHT unit. Endoscopic tests were performed when there was suspicion of GI bleeding, and patients were divided as follows: with, without, and with unsuspected GI involvement. Results: 67 (27.9%) patients with, 28 (11.7%) patients without, and 145 (60.4%) with unsuspected GI involvement were included. Age, tobacco use, endoglin (ENG) mutation, and hemoglobin were associated with GI involvement. Telangiectases were mostly in the stomach and duodenum, but 18.5% of patients with normal esophagogastroduodenoscopy (EGD) had GI involvement in video capsule endoscopy (VCE). Telangiectases ≤ 3 mm and ≤10 per location were most common. Among patients with GI disease, those with hemoglobin < 8 g/dL or transfusion requirements (65.7%) were older and had higher epistaxis severity score (ESS) and larger telangiectases (>3 mm). After a mean follow-up of 34.2 months, patients with GI involvement required more transfusions and more emergency department and hospital admissions, with no differences in mortality. Conclusions: Risk factors for GI involvement have been identified. Patients with GI involvement and severe anemia had larger telangiectases and higher ESS. VCE should be considered in patients with suspicion of GI bleeding, even if EGD is normal.

PI3K (Phosphatidylinositol 3-Kinase) Activation and Endothelial Cell Proliferation in Patients with Hemorrhagic Hereditary Telangiectasia Type 1

Hemorrhagic hereditary telangiectasia (HHT) type 2 patients have increased activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway in telangiectasia. The main objective is to evaluate the activation of the PI3K pathway in cutaneous telangiectasia of HHT1 patients. A cutaneous biopsy of a digital hand telangiectasia was performed in seven HHT1 and eight HHT2 patients and compared with six controls. The study was approved by the Clinical Research Ethics Committee of our center. A histopathological pattern with more dilated and superficial vessels that pushed up the epidermis was identified in HHT patients regardless of the type of mutation and was associated with older age, as opposed to the common telangiectasia pattern. The mean proliferation index (Ki-67) was statistically higher in endothelial cells (EC) from HHT1 than in controls. The percentage of positive EC for pNDRG1, pAKT, and pS6 in HHT1 patients versus controls resulted in higher values, statistically significant for pNDRG1 and pS6. In conclusion, we detected an increase in EC proliferation linked to overactivation of the PI3K pathway in cutaneous telangiectasia biopsies from HHT1 patients. Our results suggest that PI3K inhibitors could be used as novel therapeutic agents for HHT.

Abdominal manifestations of hereditary hemorrhagic telangiectasia: a series of 333 patients over 15 years

PURPOSE

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant multi-organ vascular disorder that commonly affects the gastrointestinal tract and the liver resulting in telangiectasias and arteriovenous malformations (AVMs). Previous studies looking at the prevalence of liver and abdominal organ involvement in HHT have been limited by differing imaging techniques and sample size limitations. We sought to define the prevalence of HHT related abdominal vascular abnormalities using optimized multiphasic contrast-enhanced abdominal computed tomography (CT) exams in a large cohort of HHT patients.

METHODS

Between January 2001 and May 2015; we identified a total of 333 consecutive HHT patients who had undergone a dedicated HHT protocol multiphase abdominal CT at our institution. The CT exams were reviewed by three board certified abdominal radiologists for the presence of vascular abnormalities involving the liver, pancreas, spleen, and other abdominal organs. Vascular abnormalities involving the liver were further categorized as telangiectasias, large confluent vascular masses, perfusion abnormalities, or hepatic shunts.

RESULTS

In patients with abdominal vascular abnormalities, the liver was the most commonly involved organ, with 180 out of 333 (54.1%) patients demonstrating at least one hepatic vascular abnormality (telangiectasia, confluent vascular mass, transient perfusion abnormalities, and hepatic shunts), with most (70.0%) demonstrating multiple hepatic vascular abnormalities. The other most common organs involved included the pancreas (18.0%), spleen (6.3%), and small bowel (4.5%).

CONCLUSION

In patients with the clinical diagnosis of HHT, greater than half demonstrate an abdominal vascular abnormality, with the most commonly involved organ being the liver. These may be under recognized on routine or single phase contrast-enhanced CT of the abdomen. This supports the use of optimized multiphasic abdominal CT exams as an important tool for the evaluation and screening of patients with HHT.

Rendu-Osler-Weber disease: a gastroenterologist's perspective

Hereditary hemorrhagic teleangectasia (HHT, or Rendu-Osler-Weber disease) is a rare inherited syndrome, characterized by arterio-venous malformations (AVMs or Telangiectasia). The most important and common manifestation is nose bleeds (epistaxis). The telangiectasias (small AVMs) are most evident on the lips, tongue, buccal mucosa, face, chest, and fingers, however; large arterio-venous malformations can also occur in the lungs, liver, pancreas, or brain. Telangiectasias in the upper gastrointestinal tract are known to occur, however data regarding possible small-bowel involvement is limited due to technical difficulties in visualizing the entire gastrointestinal tract. The occurrence of AVMs in the stomach and small bowel can result in chronic bleeding and anaemia. Less frequently, this may occur due to bleeding from oesophageal varices, as patients with HHT can develop hepatic parenchymal AVMs or vascular shunts which cause hepatic cirrhosis and portal hypertension. Gastroenterologists have a crucial role in the management of these patients, however difficulties remain in the detection and management of complications of HHT in the gastrointestinal tract.

Diagnostic yield of capsule endoscopy for small bowel arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia: a systematic review and meta-analysis

Background and study aims  Small bowel arteriovenous malformations (AVMs) pose a bleeding risk and have traditionally been diagnosed by invasive enteroscopic procedures in patients with hereditary hemorrhagic telangiectasia (HHT). Capsule endoscopy (CE) is emerging as a safe and non-invasive alternative for small intestinal evaluation, but its diagnostic yield and utility in diagnosing small bowel AVMs in HHT patients are understudied. The aim of this study was to meta-analyze the utility of CE for diagnosing AVMs in HHT patients. Methods  A meta-analysis and systematic review of the literature on CE in HHT patients identified in the PubMed, EMBASE, Scopus, and Cochrane databases from inception to March 2018 were conducted. Summary effects were estimated using a random effects model. Results  After applying exclusion criteria, five studies (n = 124 patients) were eligible for meta-analysis. The pooled diagnostic yield for visualization of small bowel AVMs by CE was 77.0 % (95 % CI 65.8 - 85.4 %, P  < 0.001). Conclusions  CE has a good diagnostic yield for small bowel AVMs in HHT. It can be regarded as a sufficient, noninvasive diagnostic modality for identifying small bowel AVMs in HHT patients.

Computerized registry of patients with hemorrhagic hereditary telangiectasia (RiHHTa Registry) in Spain: Objectives, methods, and preliminary results

INTRODUCTION

Hereditary hemorrhagic telangiectasia (HHT) is a rare disease with autosomal dominant inheritance that causes systemic vascular affectation.

MATERIAL AND METHOD

After development a multicentric Spanish national registry, called RiHHTa, main clinical manifestations and diagnostic procedures of the first patients introduced are described.

RESULTS

141 patients were included, of which 91 (64.5%) were women. The mean age at diagnosis was 42 years. Mutations in the ACVRL1 gene predominated over the ENG gene. The initial symptom was recurrent epistaxis in 130 (92.2%) patients and in three (2.1%), brain abscess. Pulmonary arteriovenous (AV) fistula were detected in 36 (45%) of the 79 patients who underwent thoracic CT angiography. The contrast echocardiography detected very few bubbles (grade I) or none, in 36 (45%) of these 79 affected patients. In 43 (67.2%) of the 64 patients with an abdominal CT angiography, hepatic vascular malformations were detected, mostly telangiectasias, AV and arterio-portal fistula, and extrahepatic in 14 (10%) subjects. More than half of the patients were screened for the presence of brain arteriovenous malformations which was found in 3.9% of them. The upper part of the intestinal tube was the most (95%) affected region.

CONCLUSION

The RiHHTa Registry allows improving the management of patients with HHT. An inadequate use of thoracic CT angiography and the usefulness of abdominal CT angiography has been detected in order to define subtypes of hepatic vascular involvement and detect extrahepatic vascular involvement.

Gastrointestinal Manifestations of Hereditary Hemorrhagic Telangiectasia (HHT): A Systematic Review of the Literature

Hereditary hemorrhagic telangiectasia (HHT), also called Osler-Weber-Rendu syndrome, is an autosomal dominant genetic disease that affects the vasculature of numerous organs. The prevalence of HHT is estimated to be between 1.5 and 2 persons per 10,000. While there is still much to learn about this condition, there is an increasing understanding its underlying pathophysiology, genetic basis, presentations, and management. Recognizing that the clinical manifestations of HHT can involve a number of organ systems will provide clinicians with a higher index of suspicion for the disease. This early diagnosis and genotyping can greatly reduce mortality for a patient with HHT through appropriate screening for complications. This review will focus on the gastrointestinal manifestations of HHT and how these can dictate treatment and prognosis.

A SMAD4 mutation indicative of juvenile polyposis syndrome in a family previously diagnosed with Menetrier's disease

BACKGROUND

Menetrier's disease (MD) is a rare disease with unknown aetiology, characterized by hypertrophic folds within the fundus and body of the stomach.

AIMS

We investigated mutations of the candidate genes SMAD4, BMPR1A, TGF-α, and PDX1 within a family with MD.

METHODS

A large 4-generation family with MD was identified. This family had 5 cases of MD, 1 case of MD and juvenile polyposis syndrome (JPS) and 3 cases of JPS. Participants provided saliva for DNA extraction and completed a health questionnaire designed to assess conditions that may be found in patients with MD. Following pedigree analysis, we sequenced the coding regions of the SMAD4 and BMPR1A genes and the regulatory regions of the TGF-α and PDX1 genes in affected and non-affected family members.

RESULTS

No mutations were identified in the sequenced regions of BMPR1A, TGF-α, or PDX1. A dominant 1244_1247delACAG mutation of SMAD4 was identified in each of the subjects with JPS as well as in each of the subjects with MD. Although this mutation segregated with disease, there were also unaffected/undiagnosed carriers.

CONCLUSION

The 1244_1247delACAG mutation of SMAD4 is the cause of JPS and the likely cause of MD in a large family initially diagnosed with MD.

Colorectal cancer risk in hamartomatous polyposis syndromes

Colorectal cancer (CRC) is a major cause of morbidity and mortality around the world, and approximately 5% of them develop in a context of inherited mutations leading to some form of familial colon cancer syndromes. Recognition and characterization of these patients have contributed to elucidate the genetic basis of CRC. Polyposis Syndromes may be categorized by the predominant histological structure found within the polyps. The aim of the present paper is to review the most important clinical features of the Hamartomatous Polyposis Syndromes, a rare group of genetic disorders formed by the peutz-Jeghers syndrome, juvenil polyposis syndrome and PTEN Hamartoma Tumor Syndrome (Bannayan-Riley-Ruvalacaba and Cowden Syndromes). A literature search was performed in order to retrieve the most recent and important papers (articles, reviews, clinical cases and clinical guidelines) regarding the studied subject. We searched for terms such as “hamartomatous polyposis syndromes”, “Peutz-Jeghers syndrome”, “juvenile polyposis syndrome”, “juvenile polyp”, and “PTEN hamartoma tumour syndrome” (Cowden syndrome, Bananyan-Riley-Ruvalcaba). The present article reports the wide spectrum of disease severity and extraintestinal manifestations, with a special focus on their potential to develop colorectal and other neoplasia. In the literature, the reported colorectal cancer risk for Juvenile Polyposis, Peutz-Jeghers and PTEN Hamartoma Tumor Syndromes are 39%-68%, 39%-57% and 18%, respectively. A review regarding cancer surveillance recommendations is also presented.

Optimal management of hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT), also known by the eponym Osler-Weber-Rendu syndrome, is a group of related disorders inherited in an autosomal dominant fashion and characterized by the development of arteriovenous malformations (AVM) in the skin, mucous membranes, and/or internal organs such as brain, lungs, and liver. Its prevalence is currently estimated at one in 5,000 to 8,000. Most cases are due to mutations in the endoglin (HHT1) or ACVRLK1 (HHT2) genes. Telangiectasias in nasal and gastrointestinal mucosa generally present with recurrent/chronic bleeding and iron deficiency anemia. Larger AVMs occur in lungs (~40%-60% of affected individuals), liver (~40%-70%), brain (~10%), and spine (~1%). Due to the devastating and potentially fatal complications of some of these lesions (for example, strokes and brain abscesses with pulmonary AVMs), presymptomatic screening and treatment are of utmost importance. However, due to the rarity of this condition, many providers lack an appreciation for the whole gamut of its manifestations and complications, age-dependent penetrance, and marked intrafamilial variation. As a result, HHT remains frequently underdiagnosed and many families do not receive the appropriate screening and treatments. This article provides an overview of the clinical features of HHT, discusses the clinical and genetic diagnostic strategies, and presents an up-to-date review of literature and detailed considerations regarding screening for visceral AVMs, preventive modalities, and treatment options.