Investigation of the Genetic Determinants of Telangiectasia and Solid Organ Arteriovenous Malformation Formation in Hereditary Hemorrhagic Telangiectasia (HHT).

Telangiectases and arteriovenous malformations (AVMs) are the characteristic lesions of Hereditary Hemorrhagic Telangiectasia (HHT). Somatic second-hit loss-of-function variations in the HHT causative genes, ENG and ACVRL1, have been described in dermal telangiectasias. It is unclear if somatic second-hit mutations also cause the formation of AVMs and nasal telangiectasias in HHT. To investigate the genetic mechanism of AVM formation in HHT, we evaluated multiple affected tissues from fourteen individuals. DNA was extracted from fresh/frozen tissue of 15 nasal telangiectasia, 4 dermal telangiectasia, and 9 normal control tissue biopsies, from nine unrelated individuals with HHT. DNA from six formalin-fixed paraffin-embedded (FFPE) AVM tissues (brain, lung, liver, and gallbladder) from five individuals was evaluated. A 736 vascular malformation and cancer gene next-generation sequencing (NGS) panel was used to evaluate these tissues down to 1% somatic mosaicism. Somatic second-hit mutations were identified in three in four AVM biopsies (75%) or half of the FFPE (50%) samples, including the loss of heterozygosity in ENG in one brain AVM sample, in which the germline mutation occurred in a different allele than a nearby somatic mutation (both are loss-of-function mutations). Eight of nine (88.9%) patients in whom telangiectasia tissues were evaluated had a somatic mutation ranging from 0.68 to 1.96% in the same gene with the germline mutation. Six of fifteen (40%) nasal and two of four (50%) dermal telangiectasia had a detectable somatic second hit. Additional low-level somatic mutations in other genes were identified in several telangiectasias. This is the first report that nasal telangiectasias and solid organ AVMs in HHT are caused by very-low-level somatic biallelic second-hit mutations.

Helix-fixed leadless pacemaker implantation through a valve-in-valve tricuspid prosthesis via the femoral approach.

Leadless pacemakers offer the opportunity to avoid transvenous hardware among patients with tricuspid valve prostheses. We present the first case of a helix-based fixation leadless pacemaker implanted through valve-in-valve tricuspid prostheses in a 43-year-old female with extensive prior cardiac history. At the time of presentation, epicardial pacing was no longer a viable option in the setting of pacemaker dependence. Placement of a helix-fixed, leadless right ventricular pacemaker was performed as a bridge to dual-chamber leadless pacing. This was safely and effectively performed and highlighted favorable procedural characteristics that included RV cavity dimensions and prosthesis type.

De Novo Brain Vascular Malformations in Hereditary Hemorrhagic Telangiectasia.

BACKGROUND: Approximately 10% of people with hereditary hemorrhagic telangiectasia (HHT) have brain vascular malformations (VMs). Few reports describe de novo brain VM formation. International HHT Guidelines recommend initial brain VM screening upon HHT diagnosis in children but do not address rescreening. We aimed to confirm whether brain VMs can form de novo in patients with HHT. METHODS: The Brain Vascular Malformation Consortium HHT project is a 17-center longitudinal study enrolling patients since 2010. We analyzed the database for de novo VMs defined as those detected (1) on follow-up neuroimaging in a patient without previous brain VMs or (2) in a location distinct from previously identified brain VMs and reported those in whom a de novo VM could be confirmed on central neuroimaging review. RESULTS: Of 1909 patients enrolled, 409 (21%) had brain VMs. Seven patients were recorded as having de novo brain VMs, and imaging was available for central review in four. We confirmed that three (0.7% of individuals with brain VMs) had de novo brain VMs (two capillary malformations, one brain arteriovenous malformation) with intervals of six, nine, and 13 years from initial imaging. Two with de novo brain VMs were <18 years. The fourth patient, a child, did not have a de novo brain VM but had a radiologically confirmed increase in size of an existing brain arteriovenous malformation. CONCLUSIONS: Brain VMs can, albeit rarely, form de novo in patients with HHT. Given the potential risk of hemorrhage from brain VMs, regular rescreening in patients with HHT may be warranted.

Brain AVM compactness score in children with hereditary hemorrhagic telangiectasia.

OBJECTIVE: The brain arteriovenous malformation (BAVM) nidus compactness score (CS), determined on angiography, predicts BAVM recurrence after surgical resection among children with sporadic BAVMs. We measured the angiographic CS for BAVMs among children with hereditary hemorrhagic telangiectasia (HHT) to determine CS characteristics in this population. METHODS: A pediatric interventional neuroradiologist reviewed angiograms to determine the CS of BAVMs in children with HHT recruited to the BVMC. CS is based on overall nidus and perinidal anomalous vessel compactness. CS categories included 1 = diffuse nidus, 2 = intermediate nidus, and 3 = compact nidus. RESULTS: Forty-eight of 78 children (61.5%) with HHT and brain vascular malformations had a conventional angiogram; 47 (97.9%) angiograms were available. Fifty-four BAVMs were identified in 40 of these 47 children (85.1%). Of 54 BAVMs in children with HHT, CS was 1 in 7 (13%), 2 in 29 (53.7%), and 3 in 18 BAVMs (33.3%) compared with CS of 1 in six (26.1%), 2 in 15 (65.2%), and 3 in 2 BAVMs (8.7%) among 23 previously reported children with sporadic BAVMs, p = 0.045 (Fisher's exact). Seven children with HHT had intracranial hemorrhage: 4 had CS = 3, 1 had CS = 2, and 2 had CS = 1. CONCLUSIONS: A range of CSs exists across HHT BAVMs, suggesting it may be an angiographic measure of interest for future studies of BAVM recurrence and hemorrhage risk. Children with HHT may have more compact niduses compared to children with sporadic BAVMs. Additional research should determine whether CS affects hemorrhage risk or post-surgical recurrence risk in HHT-associated BAVMs, which could be used to direct BAVM treatment.

Reply to Eker et al. Comment on "Kilian et al. Comparing Characteristics and Treatment of Brain Vascular Malformations in Children and Adults with HHT. J. Clin. Med. 2023, 12, 2704".

We are grateful to Eker et al. for their thoughtful analysis and response to our publication titled Comparing Characteristics and Treatment of Brain Vascular Malformations in Children and Adults with HHT [...].

Nonsense Variant PRDM16-Q187X Causes Impaired Myocardial Development and TGF-ß Signaling Resulting in Noncompaction Cardiomyopathy in Humans and Mice.

BACKGROUND: PRDM16 plays a role in myocardial development through TGF-ß (transforming growth factor-beta) signaling. Recent evidence suggests that loss of PRDM16 expression is associated with cardiomyopathy development in mice, although its role in human cardiomyopathy development is unclear. This study aims to determine the impact of PRDM16 loss-of-function variants on cardiomyopathy in humans. METHODS: Individuals with PRDM16 variants were identified and consented. Induced pluripotent stem cell-derived cardiomyocytes were generated from a proband hosting a Q187X nonsense variant as an in vitro model and underwent proliferative and transcriptional analyses. CRISPR (clustered regularly interspaced short palindromic repeats)-mediated knock-in mouse model hosting the Prdm16Q187X allele was generated and subjected to ECG, histological, and transcriptional analysis. RESULTS: We report 2 probands with loss-of-function PRDM16 variants and pediatric left ventricular noncompaction cardiomyopathy. One proband hosts a PRDM16-Q187X variant with left ventricular noncompaction cardiomyopathy and demonstrated infant-onset heart failure, which was selected for further study. Induced pluripotent stem cell-derived cardiomyocytes prepared from the PRDM16-Q187X proband demonstrated a statistically significant impairment in myocyte proliferation and increased apoptosis associated with transcriptional dysregulation of genes implicated in cardiac maturation, including TGF-ß-associated transcripts. Homozygous Prdm16Q187X/Q187X mice demonstrated an underdeveloped compact myocardium and were embryonically lethal. Heterozygous Prdm16Q187X/WT mice demonstrated significantly smaller ventricular dimensions, heightened fibrosis, and age-dependent loss of TGF-ß expression. Mechanistic studies were undertaken in H9c2 cardiomyoblasts to show that PRDM16 binds TGFB3 promoter and represses its transcription. CONCLUSIONS: Novel loss-of-function PRDM16 variant impairs myocardial development resulting in noncompaction cardiomyopathy in humans and mice associated with altered TGF-ß signaling.

Frequency of epistaxis and telangiectasia in patients with hereditary hemorrhagic telangiectasia (HHT) in comparison with the general population: Curaçao diagnostic criteria revisited.

PURPOSE: The Curaçao criteria are well-established diagnostic criteria for hereditary hemorrhagic telangiectasia (HHT), but they lack details regarding a predictive presentation of epistaxis and telangiectasias. This study collects and compares data in HHT and population cohorts to inform the application of these criteria. METHODS: In-person interviews regarding epistaxis and targeted examination for telangiectases in a general population cohort (n = 204) and an HHT cohort (n = 432) were conducted. RESULTS: Frequency of epistaxis, rather than intensity or duration, was the best discriminator of HHT. A cutoff of ≥4 nosebleeds per year alone yielded a diagnostic sensitivity of 97%, and specificity of 84%. The mean number of telangiectases at the sites investigated was 0.4 in the general population cohort and 26.5 in the HHT cohort. The most distinctive sites for telangiectases in HHT were lips and palmar fingers, whereas telangiectases of the face and dorsum of the hand were comparable in both cohorts. CONCLUSION: We propose that the Curaçao criteria be modified to include the following cutoffs: (1) epistaxis frequency of ≥4 nosebleeds per year and (2) telangiectasia count of at least 2 in characteristic locations (palmar aspect of fingers, lips, and oral cavity), and that cutaneous telangiectases at other sites not be considered relevant for diagnostic purposes.

Comparing Characteristics and Treatment of Brain Vascular Malformations in Children and Adults with HHT.

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant disease characterized by the development of vascular malformations (VMs) in organs such as the brain and lungs, as well as telangiectases on mucosal surfaces. Prophylactic treatment of organ VMs may prevent potential complications, such as hemorrhage. However, brain VM treatment-surgical resection, embolization, and/or radiosurgery-is not recommended for all patients due to the associated risks. Given the scarcity of data regarding HHT-related brain VM presentation and treatment trends in pediatric patients, we aim to describe the clinical presentations and the patterns of treatment of HHT-related brain VMs in a pediatric cohort, and compare pediatric trends to those of adults. Demographic and clinical data were analyzed in 114 pediatric patients with HHT-related brain VMs and compared with a cohort of 253 adult patients enrolled in the multicenter Brain Vascular Malformation Consortium HHT Project. Our data demonstrated that a higher proportion of pediatric patients with HHT-related brain VMs were symptomatic at presentation (p = 0.004). Moreover, a higher proportion of pediatric patients presented with intracranial hemorrhage (p < 0.001) and seizure (p = 0.002) compared to adult patients. Surgical resection was the most common brain VM treatment modality in both children and adults. We conclude that pediatric patients may be more likely to present with symptoms and complications from brain VMs, supporting the case for screening for brain VMs in children with HHT.

Choroidal melanoma with synchronous Fuchs' adenoma and novel ATRX mutation.

BACKGROUND: To report a case of Fuchs' adenoma occurring in an eye with a large choroidal melanoma. We have reviewed the literature to describe the clinical presentation, ultrasound characteristics and pathological features of these entities. CASE PRESENTATION: A 69-year-old Caucasian man presented with vision loss from a large choroidal melanoma. Enucleation showed an incidental Fuchs' adenoma in the same eye. Whole-exome sequence analysis was also performed on the patient's blood and melanoma, which showed a rarely-reported ATRX mutation. CONCLUSIONS: Fuchs' adenoma is an under-diagnosed benign age-related hyperplasia of the non-pigmented ciliary epithelium (NPCE). Given its location and characteristics, it can be mistaken for choroidal melanoma and clinicians are reminded how to differentiate between these pathologies and that they may co-exist.

Association between pregnancy and long-term cardiac outcomes in individuals with congenital heart disease.

BACKGROUND: As early life interventions for congenital heart disease improve, more patients are living to adulthood and are considering pregnancy. Scoring and classification systems predict the maternal cardiovascular risk of pregnancy in the context of congenital heart disease, but these scoring systems do not assess the potential subsequent risks following pregnancy. Data on the long-term cardiac outcomes after pregnancy are unknown for most lesion types. This limits the ability of healthcare practitioners to thoroughly counsel patients who are considering pregnancy in the setting of congenital heart disease. OBJECTIVE: We aimed to evaluate the association between pregnancy and the subsequent long-term cardiovascular health of individuals with congenital heart disease. STUDY DESIGN: This was a retrospective longitudinal cohort study of individuals identifying as female who were receiving care in two adult congenital heart disease centers from 2014 to 2019. Patient data were abstracted longitudinally from a patient age of 15 years (or from the time of entry into the healthcare system) to the conclusion of the study, death, or exit from the healthcare system. The primary endpoint, a composite adverse cardiac outcome (death, stroke, heart failure, unanticipated cardiac surgery, or a requirement for a catheterized procedure), was compared between parous (at least one pregnancy >20 weeks' gestation) and nulliparous individuals. By accounting for differences in the follow-up, the effect of pregnancy was estimated based on the time to the composite adverse outcome in a proportional hazards regression model adjusted for the World Health Organization class, baseline cardiac medications, and number of previous sternotomies. Participants were also categorized according to their lesion type, including septal defects (ventricular septal defects, atrial septal defects, atrioventricular septal defects, or atrioventricular canal defects), right-sided valvular lesions, left-sided valvular lesions, complex cardiac anomalies, and aortopathies, to evaluate if there is a differential effect of pregnancy on the primary outcome when adjusting for lesion type in a sensitivity analysis. RESULTS: Overall, 711 individuals were eligible for inclusion; 209 were parous and 502 nulliparous. People were classified according to the World Health Organization classification system with 86 (12.3%) being classified as class I, 76 (10.9%) being classified as class II, 272 (38.9%) being classified as class II to III, 155 (22.1%) being classified as class III, and 26 (3.7%) being classified as class IV. Aortic stenosis, bicuspid aortic valve, dilated ascending aorta or aortic root, aortic regurgitation, and pulmonary insufficiency were more common in parous individuals, whereas dextro-transposition of the great arteries, Turner syndrome, hypoplastic right heart, left superior vena cava, and other cardiac diagnoses were more common in nulliparous individuals. In multivariable modeling, pregnancy was associated with the composite adverse cardiac outcome (36.4%% vs 26.1%%; hazard ratio, 1.83; 95% confidence interval, 1.25-2.66). Parous individuals were more likely to have unanticipated cardiac surgery (28.2% vs 18.1%; P=.003). No other individual components of the primary outcome were statistically different between parous and nulliparous individuals in cross-sectional comparisons. The association between pregnancy and the primary outcome was similar in a sensitivity analysis that adjusted for cardiac lesion type (hazard ratio, 1.61; 95% confidence interval, 1.10-2.36). CONCLUSION: Among individuals with congenital heart disease, pregnancy was associated with an increase in subsequent long-term adverse cardiac outcomes. These data may inform counseling of individuals with congenital heart disease who are considering pregnancy.

Late-in-life treadmill training rejuvenates autophagy, protein aggregate clearance, and function in mouse hearts.

Protein quality control mechanisms decline during the process of cardiac aging. This enables the accumulation of protein aggregates and damaged organelles that contribute to age-associated cardiac dysfunction. Macroautophagy is the process by which post-mitotic cells such as cardiomyocytes clear defective proteins and organelles. We hypothesized that late-in-life exercise training improves autophagy, protein aggregate clearance, and function that is otherwise dysregulated in hearts from old vs. adult mice. As expected, 24-month-old male C57BL/6J mice (old) exhibited repressed autophagosome formation and protein aggregate accumulation in the heart, systolic and diastolic dysfunction, and reduced exercise capacity vs. 8-month-old (adult) mice (all p < 0.05). To investigate the influence of late-in-life exercise training, additional cohorts of 21-month-old mice did (old-ETR) or did not (old-SED) complete a 3-month progressive resistance treadmill running program. Body composition, exercise capacity, and soleus muscle citrate synthase activity improved in old-ETR vs. old-SED mice at 24 months (all p < 0.05). Importantly, protein expression of autophagy markers indicate trafficking of the autophagosome to the lysosome increased, protein aggregate clearance improved, and overall function was enhanced (all p < 0.05) in hearts from old-ETR vs. old-SED mice. These data provide the first evidence that a physiological intervention initiated late-in-life improves autophagic flux, protein aggregate clearance, and contractile performance in mouse hearts.

Cardiac-specific deletion of voltage dependent anion channel 2 leads to dilated cardiomyopathy by altering calcium homeostasis.

Voltage dependent anion channel 2 (VDAC2) is an outer mitochondrial membrane porin known to play a significant role in apoptosis and calcium signaling. Abnormalities in calcium homeostasis often leads to electrical and contractile dysfunction and can cause dilated cardiomyopathy and heart failure. However, the specific role of VDAC2 in intracellular calcium dynamics and cardiac function is not well understood. To elucidate the role of VDAC2 in calcium homeostasis, we generated a cardiac ventricular myocyte-specific developmental deletion of Vdac2 in mice. Our results indicate that loss of VDAC2 in the myocardium causes severe impairment in excitation-contraction coupling by altering both intracellular and mitochondrial calcium signaling. We also observed adverse cardiac remodeling which progressed to severe cardiomyopathy and death. Reintroduction of VDAC2 in 6-week-old knock-out mice partially rescued the cardiomyopathy phenotype. Activation of VDAC2 by efsevin increased cardiac contractile force in a mouse model of pressure-overload induced heart failure. In conclusion, our findings demonstrate that VDAC2 plays a crucial role in cardiac function by influencing cellular calcium signaling. Through this unique role in cellular calcium dynamics and excitation-contraction coupling VDAC2 emerges as a plausible therapeutic target for heart failure.

Systemic and CNS manifestations of inherited cerebrovascular malformations.

Cerebrovascular malformations occur in both sporadic and inherited patterns. This paper reviews imaging and clinical features of cerebrovascular malformations with a genetic basis. Genetic diseases such as familial cerebral cavernous malformations and hereditary hemorrhagic telangiectasia often have manifestations in bone, skin, eyes, and visceral organs, which should be recognized. Genetic and molecular mechanisms underlying the inherited disorders are becoming better understood, and treatments are likely to follow. An interaction between the intestinal microbiome and formation of cerebral cavernous malformations has emerged, with possible treatment implications. Two-hit mechanisms are involved in these disorders, and additional triggering mechanisms are part of the development of malformations. Hereditary hemorrhagic telangiectasia encompasses a variety of vascular malformations, with widely varying risks, and a more recently recognized association with cortical malformations. Somatic mutations are implicated in the genesis of some sporadic malformations, which means that discoveries related to inherited disorders may aid treatment of sporadic cases. This paper summarizes the current state of knowledge of these conditions, salient features regarding mechanisms of development, and treatment prospects.

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.

Distinct cellular roles for PDCD10 define a gut-brain axis in cerebral cavernous malformation.

Cerebral cavernous malformation (CCM) is a genetic, cerebrovascular disease. Familial CCM is caused by genetic mutations in KRIT1, CCM2, or PDCD10 Disease onset is earlier and more severe in individuals with PDCD10 mutations. Recent studies have shown that lesions arise from excess mitogen-activated protein kinase kinase kinase 3 (MEKK3) signaling downstream of Toll-like receptor 4 (TLR4) stimulation by lipopolysaccharide derived from the gut microbiome. These findings suggest a gut-brain CCM disease axis but fail to define it or explain the poor prognosis of patients with PDCD10 mutations. Here, we demonstrate that the gut barrier is a primary determinant of CCM disease course, independent of microbiome configuration, that explains the increased severity of CCM disease associated with PDCD10 deficiency. Chemical disruption of the gut barrier with dextran sulfate sodium augments CCM formation in a mouse model, as does genetic loss of Pdcd10, but not Krit1, in gut epithelial cells. Loss of gut epithelial Pdcd10 results in disruption of the colonic mucosal barrier. Accordingly, loss of Mucin-2 or exposure to dietary emulsifiers that reduce the mucus barrier increases CCM burden analogous to loss of Pdcd10 in the gut epithelium. Last, we show that treatment with dexamethasone potently inhibits CCM formation in mice because of the combined effect of action at both brain endothelial cells and gut epithelial cells. These studies define a gut-brain disease axis in an experimental model of CCM in which a single gene is required for two critical components: gut epithelial function and brain endothelial signaling.

Biomarkers of cavernous angioma with symptomatic hemorrhage.

BACKGROUNDCerebral cavernous angiomas (CAs) with a symptomatic hemorrhage (CASH) have a high risk of recurrent hemorrhage and serious morbidity.METHODSEighteen plasma molecules with mechanistic roles in CA pathobiology were investigated in 114 patients and 12 healthy subjects. The diagnostic biomarker of a CASH in the prior year was derived as that minimizing the Akaike information criterion and validated using machine learning, and was compared with the prognostic CASH biomarker predicting bleeding in the subsequent year. Biomarkers were longitudinally followed in a subset of cases. The biomarkers were queried in the lesional neurovascular unit (NVU) transcriptome and in plasma miRNAs from CASH and non-CASH patients.RESULTSThe diagnostic CASH biomarker included a weighted combination of soluble CD14 (sCD14), VEGF, C-reactive protein (CRP), and IL-10 distinguishing CASH patients with 76% sensitivity and 80% specificity (P = 0.0003). The prognostic CASH biomarker (sCD14, VEGF, IL-1ß, and sROBO-4) was confirmed to predict a bleed in the subsequent year with 83% sensitivity and 93% specificity (P = 0.001). Genes associated with diagnostic and prognostic CASH biomarkers were differentially expressed in CASH lesional NVUs. Thirteen plasma miRNAs were differentially expressed between CASH and non-CASH patients.CONCLUSIONShared and unique biomarkers of recent symptomatic hemorrhage and of future bleeding in CA are mechanistically linked to lesional transcriptome and miRNA. The biomarkers may be applied for risk stratification in clinical trials and developed as a tool in clinical practice.FUNDINGNIH, William and Judith Davis Fund in Neurovascular Surgery Research, Be Brave for Life Foundation, Safadi Translational Fellowship, Pritzker School of Medicine, and Sigrid Jusélius Foundation.

A novel phosphoglucomutase-deficient mouse model reveals aberrant glycosylation and early embryonic lethality.

Patients with phosphoglucomutase (PGM1) deficiency, a congenital disorder of glycosylation (CDG) suffer from multiple disease phenotypes. Midline cleft defects are present at birth. Overtime, additional clinical phenotypes, which include severe hypoglycemia, hepatopathy, growth retardation, hormonal deficiencies, hemostatic anomalies, frequently lethal, early-onset of dilated cardiomyopathy and myopathy emerge, reflecting the central roles of the enzyme in (glycogen) metabolism and glycosylation. To delineate the pathophysiology of the tissue-specific disease phenotypes, we constructed a constitutive Pgm2 (mouse ortholog of human PGM1)-knockout (KO) mouse model using CRISPR-Cas9 technology. After multiple crosses between heterozygous parents, we were unable to identify homozygous life births in 78 newborn pups (P = 1.59897E-06), suggesting an embryonic lethality phenotype in the homozygotes. Ultrasound studies of the course of pregnancy confirmed Pgm2-deficient pups succumb before E9.5. Oral galactose supplementation (9 mg/mL drinking water) did not rescue the lethality. Biochemical studies of tissues and skin fibroblasts harvested from heterozygous animals confirmed reduced Pgm2 enzyme activity and abundance, but no change in glycogen content. However, glycomics analyses in serum revealed an abnormal glycosylation pattern in the Pgm2+/- animals, similar to that seen in PGM1-CDG.

Localization and age distribution of telangiectases in children and adolescents with hereditary hemorrhagic telangiectasia: A retrospective cohort study.

BACKGROUND: The location of telangiectases in hereditary hemorrhagic telangiectasia (HHT), as set forth in the consensus diagnostic (Curaçao) criteria, is based primarily on adults. OBJECTIVE: Document the locations and numbers of telangiectases in a cohort of pediatric patients with HHT. METHODS: A retrospective chart review using a standardized data collection form for site and number of telangiectases was performed for pediatric patients with HHT (age, 0-18 years) from 2005 to 2016. RESULTS: Of 90 pediatric patients with HHT, 71% had one or more telangiectases. Of all the telangiectases counted (N = 319), cutaneous telangiectases were more common (73%) than oral telangiectases (27%). The hands were the most frequent site, accounting for 33% of all telangiectases. Adolescents were more likely than children to have cutaneous telangiectases (85% vs 50% [Q = 0.005]). The most frequent sites in children younger than 10 years were the hands excluding the fingers (27%), fingers (25%), and face (23%). Only 23% of subjects (21 of 90) presented with multiple (≥3) telangiectases at locations considered characteristic for the current consensus diagnosis guidelines (lips, oral cavity, and fingers). LIMITATIONS: Ascertainment bias based on recruitment. CONCLUSIONS: In this pediatric population, telangiectases at sites not included as "characteristic" by the Curaçao diagnostic criteria were common. The Curaçao criteria in regard to both number and location of telangiectases may be inadequate in the pediatric HHT population.

Atorvastatin Treatment of Cavernous Angiomas with Symptomatic Hemorrhage Exploratory Proof of Concept (AT CASH EPOC) Trial.

BACKGROUND: More than a million Americans harbor a cerebral cavernous angioma (CA), and those who suffer a prior symptomatic hemorrhage have an exceptionally high rebleeding risk. Preclinical studies show that atorvastatin blunts CA lesion development and hemorrhage through inhibiting RhoA kinase (ROCK), suggesting it may confer a therapeutic benefit. OBJECTIVE: To evaluate whether atorvastatin produces a difference compared to placebo in lesional iron deposition as assessed by quantitative susceptibility mapping (QSM) on magnetic resonance imaging in CAs that have demonstrated a symptomatic hemorrhage in the prior year. Secondary aims shall assess effects on vascular permeability, ROCK activity in peripheral leukocytes, signal effects on clinical outcomes, adverse events, and prespecified subgroups. METHODS: The phase I/IIa placebo-controlled, double-blinded, single-site clinical trial aims to enroll 80 subjects randomized 1-1 to atorvastatin (starting dose 80 mg PO daily) or placebo. Dosing shall continue for 24-mo or until reaching a safety endpoint. EXPECTED OUTCOMES: The trial is powered to detect an absolute difference of 20% in the mean percent change in lesional QSM per year (2-tailed, power 0.9, alpha 0.05). A decrease in QSM change would be a signal of potential benefit, and an increase would signal a safety concern with the drug. DISCUSSION: With firm mechanistic rationale, rigorous preclinical discoveries, and biomarker validations, the trial shall explore a proof of concept effect of a widely used repurposed drug in stabilizing CAs after a symptomatic hemorrhage. This will be the first clinical trial of a drug aimed at altering rebleeding in CA.

Genome sequencing reveals a deep intronic splicing ACVRL1 mutation hotspot in Hereditary Haemorrhagic Telangiectasia.

INTRODUCTION: Hereditary haemorrhagic telangiectasia (HHT) is a genetically heterogeneous disorder caused by mutations in the genes ENG, ACVRL1, and SMAD4. Yet the genetic cause remains unknown for some families even after exhaustive exome analysis. We hypothesised that non-coding regions of the known HHT genes may harbour variants that disrupt splicing in these cases. METHODS: DNA from 35 individuals with clinical findings of HHT and 2 healthy controls from 13 families underwent whole genome sequencing. Additionally, 87 unrelated cases suspected to have HHT were evaluated using a custom designed next-generation sequencing panel to capture the coding and non-coding regions of ENG, ACVRL1 and SMAD4. Individuals from both groups had tested negative previously for a mutation in the coding region of known HHT genes. Samples were sequenced on a HiSeq2500 instrument and data were analysed to identify novel and rare variants. RESULTS: Eight cases had a novel non-coding ACVRL1 variant that disrupted splicing. One family had an ACVRL1intron 9:chromosome 3 translocation, the first reported case of a translocation causing HHT. The other seven cases had a variant located within a ~300 bp CT-rich 'hotspot' region of ACVRL1intron 9 that disrupted splicing. CONCLUSIONS: Despite the difficulty of interpreting deep intronic variants, our study highlights the importance of non-coding regions in the disease mechanism of HHT, particularly the CT-rich hotspot region of ACVRL1intron 9. The addition of this region to HHT molecular diagnostic testing algorithms will improve clinical sensitivity.