Does severe bleeding in HHT patients respond to intravenous bevacizumab? Review of the literature and case series.

BACKGROUND: Hereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominant genetic disorder, with a wide variety of clinical manifestations due to the presence of multiple arteriovenous manifestations. Severe bleeding from the gastrointestinal (GI) tract and/or epistaxis presents a significant problem in a subgroup of patients and systemic bevacizumab, an angiogenesis inhibitor, has been suggested to benefit these patients. OBJECTIVE: To perform a review of the literature concerning the efficacy of systemic bevacizumab in treatment of bleeding from the nose or GI tract in patients with HHT, including patients from our own HHT-center. METHODS: A literature review was performed using the guideline "Preferred Reporting Items for systematic Reviews and MetaAnalysis statement" (PRISMA). RESULTS: After careful selection, we finally analysed the results of eight case series and 33 case reports. Among 195 patients 171 (88%) had reduced bleeding after bevacizumab. CONCLUSIONS: Based on the literature review and data from our own case series, systemic bevacizumab is very promising as treatment for HHT patients with severe epistaxis and/or GI-bleeding. However, care should be taken using bevacizumab, a potent angiogenesis inhibitor; long-term side effects have not been studied in this population. A randomized controlled study is warranted to support the results in HHT patients.

Pulmonary arteriovenous malformations: a radiological and clinical investigation of 136 patients with long-term follow-up.

AIM: To assess the clinical outcome of patients with and without hereditary haemorrhagic telangiectasia (HHT) after embolisation of pulmonary arteriovenous malformations (PAVM) from a single national centre. MATERIALS AND METHODS: The present register-based observational study including all patients with PAVM treated with embolisation at a reference centre for HHT and PAVM was undertaken over a 20-year period. Demographic data, HHT genotyping, clinical presentation, and outcome were registered. Patients with HHT were compared to the patients without HHT. Clinical examination, contrast-enhanced echocardiography, and computed tomography (CT) were used to assess the clinical outcome at follow-up. RESULTS: One hundred and thirty-six patients with 339 PAVM underwent embolisation during the study period: 22 did not have HHT; 62% had HHT1, 10% had HHT2, 4% had JP-HHT, 8% had clinical HHT without identified genetic mutations. Solitary PAVM were more common among patients without HHT than with HHT. Mean follow-up after the first embolisation was 58 months. Mean age at first embolisation was 46.5 years, and at last follow-up 51.8 years. The clinical success without shunt at follow-up was 87%. The 30-day mortality related to the embolisation was 0%. Twenty patients died during follow-up (mean age 69 years). Most patients could be treated during one session, but many will need a long follow-up with repeated clinical examinations and embolisation. CONCLUSION: The majority of patients referred for embolisation of PAVM had HHT. Multiple PAVM is associated with HHT. Patients with PAVM should be screened for HHT and patients with HHT for PAVM. Embolisation is a safe procedure with high clinical success.

The validity of nasal endoscopy in patients with chronic rhinosinusitis-An inter-rater agreement study.

OBJECTIVES: Nasal endoscopy is a cornerstone in diagnosing sinonasal disease, but different raters might generate different results using the technique. Our study aims to evaluate the agreement between multiple raters to assess the validity of nasal endoscopy. DESIGN/PARTICIPANTS: Three independent and blinded raters evaluated 28 patients (56 nasal cavities) diagnosed with chronic rhinosinusitis according to the European Position Paper on Rhinosinusitis and Nasal Polyps. The ratings were compared using unweighted Fleiss' kappa coefficients (Kf ) for each objective parameter. SETTING: The department of Otorhinolaryngology, Odense University Hospital, Denmark. MAIN OUTCOME MEASURES: The ratings were quantified in a modified Lund-Kennedy endoscopy score and focused on the objective parameters specified in the diagnostic criteria: polyps, oedema and discharge. RESULTS: The raters agreed on the findings concerning polyps and discharge but not regarding oedema with the inter-rater agreement for the different parameters being: polyps Kf =.66 (SE .07, P<.001), oedema Kf =.05 (SE .07, P=.21), discharge Kf =.35 (SE .08, P<.001), oedema exclusively in middle meatus Kf =-.07 (SE .04, P=.8) and discharge exclusively in middle meatus Kf =.16 (SE .07, P=.01). CONCLUSION: Using nasal endoscopy, the evaluation of polyps by multiple raters showed sufficient reliability indicating an acceptable objective evaluation. The evaluation of discharge achieved a fair level of agreement while the assessment of oedema could not achieve a sufficient reliability questioning the inclusion of oedema in the criteria for diagnosing sinonasal disease.

Prevalence of hereditary hemorrhagic telangiectasia in patients operated for cerebral abscess: a retrospective cohort analysis.

It is well described that patients with pulmonary arteriovenous malformations (PAVMs) and Hereditary Hemorrhagic Telangiectasia (HHT) have an increased risk of cerebral abscess (CA). However, as both CA and HHT are rare, the proportion of patients with CA who are diagnosed with HHT has not been previously described. A retrospective study was carried out of all patients treated surgically for CA between January 1995 and September 2014 at the Department of Neurosurgery, Odense University Hospital. The cases were then cross-referenced with the Danish HHT database. Eighty patients aged 5-79 years were included. The incidence of CA was 0.33/100,000/year. Two patients (2.5%) were registered as having HHT. Bacterial pathogens were identified in 70% of all cases, most frequently streptococci species (46.3%). The most common predisposing condition was odontogenic infection (20%), followed by post-operative infection (13.8%) and post-trauma (6.3%). Patients undergoing a full diagnostic program to determine predisposing conditions causing CA increased over the 20-year period from 11.8% to 65.2%. The 3-month and 1-year mortality rates were 7.5% and 11.25%, respectively. There is an overrepresentation of HHT patients in a cohort of patients with CA, and HHT should be investigated as the cause of the CA if no other apparent cause can be identified.

EUFOREA Rhinology Research Forum 2016: report of the brainstorming sessions on needs and priorities in rhinitis and rhinosinusitis.

The first European Rhinology Research Forum organized by the European Forum for Research and Education in Allergy and Airway Diseases (EUFOREA) was held in the Royal Academy of Medicine in Brussels on 17th and 18th November 2016, in collaboration with the European Rhinologic Society (ERS) and the Global Allergy and Asthma European Network (GA2LEN). One hundred and thirty participants (medical doctors from different specialties, researchers, as well as patients and industry representatives) from 27 countries took part in the multiple perspective discussions including brainstorming sessions on care pathways and research needs in rhinitis and rhinosinusitis. The debates started with an overview of the current state of the art, including weaknesses and strengths of the current practices, followed by the identification of essential research needs, thoroughly integrated in the context of Precision Medicine (PM), with personalized care, prediction of success of treatment, participation of the patient and prevention of disease as key principles for improving current clinical practices. This report provides a concise summary of the outcomes of the brainstorming sessions of the European Rhinology Research Forum 2016.

JP-HHT phenotype in Danish patients with SMAD4 mutations.

Patients with germline mutations in SMAD4 can present symptoms of both juvenile polyposis syndrome (JPS) and hereditary hemorrhagic telangiectasia (HHT): the JP-HHT syndrome. The complete phenotypic picture of this syndrome is only just emerging. We describe the clinical characteristics of 14 patients with SMAD4-mutations. The study was a retrospective, register-based study. SMAD4 mutations carriers were identified through the Danish HHT-registry, the genetic laboratories - and the genetic departments in Denmark. The medical files from relevant departments were reviewed and symptoms of HHT, JPS, aortopathy and family history were noted. We detected 14 patients with SMAD4 mutations. All patients had polyps removed and 11 of 14 fulfilled the diagnostic criteria for JPS. Eight patients were screened for HHT-symptoms and seven of these fulfilled the Curaçao criteria. One patient had aortic root dilation. Our findings support that SMAD4 mutations carriers have symptoms of both HHT and JPS and that the frequency of PAVM and gastric involvement with polyps is higher than in patients with HHT or JPS not caused by a SMAD4 mutation. Out of eight patients screened for aortopathy, one had aortic root dilatation, highlighting the need for additional screening for aortopathy.

Efficacy of ESS in chronic rhinosinusitis with and without nasal polyposis: a Danish cohort study.

Endoscopic sinus surgery (ESS) for patients with severe chronic rhinosinusitis (CRS) has become a well-established treatment in cases where medical therapy fails. Even though CRS patients are divided into two subgroups, CRS with nasal polyposis (CRSwNP) and CRS without nasal polyposis (CRSsNP), most studies present only results for the total cohort. This prospective cohort study evaluated the efficacy of ESS on both quality of life and olfactory function measures, in a cohort of Danish CRS patients diagnosed according to the EPOS criteria, with results analysed separately for the CRSwNP and CRSsNP subgroups. All 97 CRS patients who underwent ESS over an 18-month trial period were evaluated preoperative by SNOT-22 score, Sniffin' Sticks score, modified Lund-Kennedy endoscopic score and Lund-Mackay CT score. Patient outcomes were reevaluated at clinical follow-up 1 and 6 months postoperative. ESS efficiently and immediately improved quality of life for both CRSwNP and CRSsNP patients, with over 50 % reduction in SNOT-22 score 1 month after surgery, which sustained 6 months postoperative. Olfactory function measured by Sniffin' Sticks score showed overall improvement in both groups. ESS efficiently improved quality of life in both CRSwNP and CRSsNP patients, and surgery lead to an overall improvement in olfactory function. However, a minor proportion of patients experienced deterioration in olfactory function after ESS.

The Sinonasal Outcome Test 22 score in persons without chronic rhinosinusitis.

OBJECTIVES: To determine the Sinonasal Outcome Test 22 (SNOT 22) score in persons without chronic rhinosinusitis. DESIGN AND SETTING: As part of a trans-European study selected, respondents to a survey questionnaire were invited for a clinical visit. Subjective symptoms and rhinoscopy were used for the clinical diagnosis of chronic rhinosinusitis according to EPOS. PARTICIPANTS: A total of 366 persons participated at the clinical visit and of these 268 did not have chronic rhinosinusitis. All participants completed the SNOT 22. MAIN OUTCOME MEASURES: The SNOT 22. RESULTS: The SNOT 22 score ranged from 0 to 67 with a mean score of 10.5 (CI: 9.1-11.9) and the median score was 7. Persons with allergic rhinitis and blue-collar workers had a significant higher score. CONCLUSION: The median value of 7 is taken as the normal SNOT 22 score in persons without CRS and can be used as a reference in clinical settings and research. Allergic rhinitis and occupation affect SNOT 22 in persons without CRS.

National mutation study among Danish patients with hereditary haemorrhagic telangiectasia.

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominantly inherited vascular disease characterized by the presence of mucocutaneous telangiectasia and visceral arteriovenous malformations (AVM). The clinical diagnosis of HHT is based on the Curaçao criteria. About 85% of HHT patients carry mutations in the ENG, ACVRL1 or SMAD4 genes. Here, we report on the genetic heterogeneity in the Danish national HHT population and address the prevalence of pulmonary arteriovenous malformations (PAVM). Probands of 107 apparently unrelated families received genetic testing, including sequencing and multiplex ligation-dependent probe amplification (MLPA) analyses of ENG, ACVRL1 and SMAD4. These 107 families included 320 patients confirmed to have HHT either clinically or genetically. In 89% of the probands (n=95), a mutation was identified. We detected 64 unique mutations of which 27 (41%) were novel. Large deletions were identified in ENG and ACVRL1. The prevalence of PAVM was 52.3% in patients with an ENG mutation and 12.9% in the ACVRL1 mutation carriers. We diagnosed 80% of the patients clinically, fulfilling the Curaçao criteria, and those remaining were diagnosed by genetic testing. It is discussed when to assign pathogenicity to missense and splice site mutations. The adding of an extra criterion to the Curaçao criteria is suggested.

Cerebral abscesses among Danish patients with hereditary haemorrhagic telangiectasia.

BACKGROUND: Hereditary haemorrhagic telangiectasia (HHT) is a dominantly inherited disease characterized by a wide variety of clinical manifestations, including pulmonary arteriovenous malformations (PAVMs), which due to paradoxical embolization may cause cerebral abscess. OBJECTIVE: To estimate the risk of cerebral abscess among patients with HHT. METHODS: All patients with HHT included in the Danish HHT data base, between January 1995 and October 2012, have been clinically evaluated for the presence of neurological symptoms and history of previous cerebral abscess. RESULTS: A total of 337 patients with HHT have been included in the Danish database. Of these, 264 were screened for the presence of PAVM. In 117 patients, a PAVM was diagnosed; among these, we identified nine patients with a history of cerebral abscess. The prevalence of cerebral abscess among patients with HHT and PAVM was therefore 7.8%. The patients with a history of cerebral abscess were genetically evaluated, and seven had ENG mutations, one had an ALK1 mutation, and in one case, a mutation could not be identified. CONCLUSION: Patients with untreated PAVM have a considerable risk of sustaining cerebral abscesses. A cerebral abscess may be the first symptom leading to an HHT diagnosis. Patients with unexplained cerebral abscess should be evaluated for HHT and PAVM.

Acoustic rhinometry in persons recruited from the general population and diagnosed with chronic rhinosinusitis according to EPOS.

Chronic rhinosinusitis (CRS) is a disease related to the nose and the paranasal sinus as defined by the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) criteria. The criteria include subjective symptoms, such as nasal obstruction, and objective findings by endoscopy. Acoustic rhinometry (AR) is an objective method to determine nasal cavity geometry. The technique is based on a sound pulse reflection analysis in the nasal cavity and determines cross-sectional areas as a function of distance as well as volume. AR measurements in persons recruited from the general population, with and without CRS based on the clinical EPOS criteria, were investigated. As part of a trans-European study, 362 persons, comprising 91 persons with CRS and 271 persons without CRS, were examined by an otolaryngologist including rhinoscopy. Minimum cross-sectional area, distance to minimum cross-sectional area, and volume in the nasal cavity were measured by acoustic rhinometry and all participants underwent Peak Nasal Inspiratory Flow (PNIF) and allergy test. A difference in AR was found before and after decongestion, but no difference was seen between CRS patients and controls. Positive correlation between AR and PNIF was found and AR was capable of identifying mucosal oedema and septum deviation visualised by rhinoscopy. In conclusion, AR, as a single instrument, was not capable of discriminating persons with CRS from persons without CRS in the general population. However, AR correlates well with PNIF and was capable of identifying septum deviation and mucosal oedema.

Diagnosing chronic rhinosinusitis: comparing questionnaire-based and clinical-based diagnosis.

BACKGROUND: The European Position Paper on Rhinosinusitis and Nasal Polyps (EP3OS) incorporates symptomatic and endo- scopic criteria in the clinical diagnosis of chronic rhinosinusitis (CRS), while in epidemiological studies the definition is based on symptoms only. The aim of this study was to evaluate the correlation between questionnaire-based and clinical-based CRS. METHODS: Based on the GA2LEN postal survey data a total of 366 persons participated at the follow-up at the Danish centre and provided information on questionnaire-based CRS. At the same occasion the 366 participants underwent clinical inter- view and examination by an otorhinolaryngologist to provide information for a clinical-based CRS diagnosis. The association between questionnaire-based and clinical-based CRS diagnosis was determined using logistic regression models and kappa statistics. RESULTS: Mean age of respondents to the postal questionnaire was 45.3 years and 52.9% were female. Persons with asthma were 8.4 % and 26.2 % were actual smokers. There was moderate agreement between questionnaire-based and clinical-based CRS. Sensitivity was [corrected] low comparing questionnaire-based CRS with clinical-based CRS. Incorporation of self reported CRS and medical history in diagnosing CRS by questionnaire increased increased [corrected] the agreement and sensitivity while specificity stayed at a high level. [corrected] CONCLUSION: Evaluating the correlation between questionnaire-based and clinical-based CRS showed only moderate agree- ment and questions whether they evaluate the same disease. It brings into consideration that adjustments are needed to justify correlation between questionnaire-based and clinical-based diagnosis of CRS.

Quality of life and associated factors in persons with chronic rhinosinusitis in the general population: a prospective questionnaire and clinical cross-sectional study.

OBJECTIVES: The European Position Paper on Rhinosinusitis and Nasal Polyps describes methods to perform population-based and clinical studies on chronic rhinosinusitis in a standardised way, and it also describes how to clinical investigate CRS. The aim of this cross-sectional study was to evaluate quality of life and objective findings in persons with chronic rhinosinusitis recruited from the general population. DESIGN: As part of a trans-European study, selected respondents to a survey questionnaire were invited for a clinical visit. Subjective symptoms and rhinoscopy were used for the clinical diagnosis of chronic rhinosinusitis, and persons with and without chronic rhinosinusitis were compared. SETTING: This research took place in the department of Otolaryngology, Odense University Hospital. PARTICIPANTS: A total of 366 persons participated at the clinical visit, and of these, 91 were diagnosed with chronic rhinosinusitis, 271 without chronic rhinosinusitis and four persons were excluded. MAIN OUTCOME MEASURES: Severity of symptoms and disease-specific quality of life were measured using the Sino-Nasal Outcome Test 22, and generic quality of life was measured using European quality of life - 5 dimensions including an index score and a visual analogue scale. RESULTS: The prevalence of chronic rhinosinusitis was 9%, and the prevalence of polyps was 4%. Persons with chronic rhinosinusitis had significantly reduced disease-specific quality of life (P = 0.00) and generic quality of life (P = 0.04 and 0.01) compared with persons without chronic rhinosinusitis. Having chronic rhinosinusitis was correlated to age, allergic rhinitis and smell. CONCLUSION: This study gives insight into health-related quality of life and objective findings in persons with chronic rhinosinusitis recruited from the general population.

The European Rare Disease Network for HHT Frameworks for management of hereditary haemorrhagic telangiectasia in general and speciality care.

Hereditary haemorrhagic telangiectasia (HHT) is a complex, multisystemic vascular dysplasia affecting approximately 85,000 European Citizens. In 2016, eight founding centres operating within 6 countries, set up a working group dedicated to HHT within what became the European Reference Network on Rare Multisystemic Vascular Diseases. By launch, combined experience exceeded 10,000 HHT patients, and Chairs representing 7 separate specialties provided a median of 24 years' experience in HHT. Integrated were expert patients who focused discussions on the patient experience. Following a 2016-2017 survey to capture priorities, and underpinned by more than 40 monthly meetings, and new data acquisitions, VASCERN HHT generated position statements that distinguish expert HHT care from non-expert HHT practice. Leadership was by specialists in the relevant sub-discipline(s), and 100% consensus was required amongst all clinicians before statements were published or disseminated. One major set of outputs targeted all healthcare professionals and their HHT patients, and include the new Orphanet definition; Do's and Don'ts for common situations; Outcome Measures suitable for all consultations; COVID-19; and anticoagulation. The second output set span aspects of vascular pathophysiology where greater understanding will assist organ-specific specialist clinicians to provide more informed care to HHT patients. These cover cerebral vascular malformations and screening; mucocutaneous telangiectasia and differential diagnosis; anti-angiogenic therapies; circulatory interplays between anaemia and arteriovenous malformations; and microbiological strategies to counteract loss of normal pulmonary capillary function. Overall, the integrated outputs, and documented current practices, provide frameworks for approaches that augment the health and safety of HHT patients in diverse health-care settings.

Safety of direct oral anticoagulants in patients with hereditary hemorrhagic telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular dysplasia resulting in visceral arteriovenous malformations and smaller mucocutaneous telangiectasia. Most patients experience recurrent nosebleeds and become anemic without iron supplementation. However, thousands may require anticoagulation for conditions such as venous thromboembolism and/or atrial fibrillation. Over decades, tolerance data has been published for almost 200 HHT-affected users of warfarin and heparins, but there are no published data for the newer direct oral anticoagulants (DOACs) in HHT. METHODS: To provide such data, a retrospective audit was conducted across the eight HHT centres of the European Reference Network for Rare Multisystemic Vascular Diseases (VASCERN), in Denmark, France, Germany, Italy, the Netherlands and the UK. RESULTS: Although HHT Centres had not specifically recommended the use of DOACs, 32 treatment episodes had been initiated by other clinicians in 28 patients reviewed at the Centres, at median age 65 years (range 30-84). Indications were for atrial fibrillation (16 treatment episodes) and venous thromboembolism (16 episodes). The 32 treatment episodes used Apixaban (n = 15), Rivaroxaban (n = 14), and Dabigatran (n = 3). HHT nosebleeds increased in severity in 24/32 treatment episodes (75%), leading to treatment discontinuation in 11 (34.4%). Treatment discontinuation was required for 4/15 (26.7%) Apixaban episodes and 7/14 (50%) Rivaroxaban episodes. By a 4 point scale of increasing severity, there was a trend for Rivaroxaban to be associated with a greater bleeding risk both including and excluding patients who had used more than one agent (age-adjusted coefficients 0.61 (95% confidence intervals 0.11, 1.20) and 0.74 (95% confidence intervals 0.12, 1.36) respectively. Associations were maintained after adjustment for gender and treatment indication. Extreme hemorrhagic responses, worse than anything experienced previously, with individual nosebleeds lasting hours requiring hospital admissions, blood transfusions and in all cases treatment discontinuation, occurred in 5/14 (35.7%) Rivaroxaban episodes compared to 3/15 (20%) Apixaban episodes and published rates of ~ 5% for warfarin and heparin. CONCLUSIONS: Currently, conventional heparin and warfarin remain first choice anticoagulants in HHT. If newer anticoagulants are considered, although study numbers are small, at this stage Apixaban appears to be associated with lesser bleeding risk than Rivaroxaban.

Middle ear disease in Danish toddlers attending nursery day-care - Applicability of OM-6, disease specific quality of life and predictors for middle ear symptoms.

OBJECTIVES: Otitis media (OM) is a very common childhood disease and impacts child quality of life (QoL) to different extends. The aim of this study was to investigate the difference in quality of life between three groups of children; Children with symptoms of ear disease within the last 4 weeks, children without any ear disease and children scheduled for ventilating tube treatment. Furthermore, we investigated predictors for experiencing middle ear symptoms. Lastly, we assessed psychometric properties of OM-6 used to assess QoL. METHODS: Four hundred ninety-four children attending nursery day-care aged 6-36 months were enrolled in the study. Caregivers were asked to recall the child's history of symptoms related to middle ear infection. The Danish version of otitis media-6 questionnaire was used to measure the children's quality of life. Data from children treated with ventilating tubes were included from a previously published study. Logistic regression was applied for determining possible predictors for experiencing ear related symptoms. RESULTS: The study had an 87% response rate, with a total of 342 children included. At the inclusion 32 (9%) children were included in the 4-week group and, while 307 children were allocated to the non-4 week group. The children in the 4-week group were significantly younger and were more likely to have siblings with a history of middle ear infection than the non-4week group. Furthermore, QoL was significantly worse in the 4-week group compared to the non-4week group. Only subtle differences were found between children with acute symptoms compared to children scheduled for tube treatment. CONCLUSIONS: As expected, children with acute symptoms of OM experience lowered QoL compared to children with no symptoms and young age as well as having siblings with a history of middle ear problems were found to be possible predictors for experiencing middle ear symptoms. Children with acute symptoms differed from children scheduled for ventilating tubes on domains related to long-term problems from OM. OM-6 has shown to be a valid instrument for assessing disease specific QoL in children with OM, however a more large-scale instrument might be necessary for detecting subtle differences between subgroups of children with OM.

Herd-level risk factors for the mortality of cows in Danish dairy herds.

The factors affecting the mortality of cows in Danish dairy herds were investigated by analysing data from 6839 herds. The mean risk of mortality during the first 100 days of lactation was 2.5 per cent. The risk of mortality increased with increasing herd size (odds ratio [OR] 1.05 for an increase in herd size of 50 cows), with the proportion of purchased cows (OR 1.05 for an increase in the proportion of purchased cows of 0.1), and with increases in the somatic cell count (OR 1.16 for an increase in average weighted mean somatic cell count of 100,000 cells/ml). The risk decreased with increasing average milk yield per cow (OR 0.93 for an increase in mean yield per cow-year of 1000 kg). The risk was lower in free-stall barns with deep litter (OR 0.79) than in barns with cubicles (OR 1) or tie-stalls (OR 1.04). Herds with Danish Holstein (OR 1) or Danish Jersey (OR 0.93) cows as the predominant breed had a higher risk of mortality than herds of the Danish red dairy breed (OR 0.67). The risk of mortality was lower in organic herds (OR 1) than in conventional herds (OR 1.17), and lower in herds that grazed pasture during the summer (OR 0.78).

Mutations in the ALK-1 gene and the phenotype of hereditary hemorrhagic telangiectasia in two large Danish families.

Mutations in the ENG gene on chromosome 9 (HHT 1) and in the ALK-1 gene on chromosome 12 (HHT 2) have been reported as causes of hereditary hemorrhagic telangiectasia (HHT). HHT 1 has been correlated with a higher prevalence of pulmonary arteriovenous malformations than HHT 2. Other distinct phenotype-genotype correlations have not been described. The prevalence of HHT in the county of Fyn, Denmark, was 15.6 per 100,000 on January 1, 1995. All living patients and their first-degree relatives were invited to attend a detailed clinical examination and blood was drawn for mutation analysis. In two families mutations were identified in exon 8 of the ALK-1 gene. In family 6 we found a T1193A mutation. In this family a high prevalence of PAVM and severe GI bleeding was documented, while in family 8 with a C1120T mutation no individuals with PAVM were identified and only one patient had a history of severe GI bleeding. No mutations in the endoglin locus were found in either family.

Diagnostic criteria for hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome).

Hereditary Hemorrhagic Telangiectasia (HHT) is easily recognized in individuals displaying the classical triad of epistaxis, telangiectasia, and a suitable family history, but the disease is more difficult to diagnosis in many patients. Serious consequences may result if visceral arteriovenous malformations, particularly in the pulmonary circulation, are unrecognized and left untreated. In spite of the identification of two of the disease-causing genes (endoglin and ALK-1), only a clinical diagnosis of HHT can be provided for the majority of individuals. On behalf of the Scientific Advisory Board of the HHT Foundation International, Inc., we present consensus clinical diagnostic criteria. The four criteria (epistaxes, telangiectasia, visceral lesions and an appropriate family history) are carefully delineated. The HHT diagnosis is definite if three criteria are present. A diagnosis of HHT cannot be established in patients with only two criteria, but should be recorded as possible or suspected to maintain a high index of clinical suspicion. If fewer than two criteria are present, HHT is unlikely, although children of affected individuals should be considered at risk in view of age-related penetration in this disorder. These criteria may be refined as molecular diagnostic tests become available in the next few years.