Familial Cerebral Cavernous Malformations Research Articles

Prevalence, genetic and clinical characteristics in first-degree relatives of patients with familial cerebral cavernous malformations in China

ObjectiveThis study aims to investigate the prevalence of familial cerebral cavernous malformations (FCCMs) in first-degree relatives (FDRs) using familial screening, to describe the distribution of initial symptoms, lesion count on...

Mild Hypoxia Accelerates Cerebral Cavernous Malformation Disease Through CX3CR1-CX3CL1 Signaling.

Heterogeneity in the severity of cerebral cavernous malformations (CCMs) disease, including brain bleedings and thrombosis that cause neurological disabilities in patients, suggests that environmental, genetic, or biological factors act as disease modifiers. Still, the underlying mechanisms are not entirely understood. Here, we report that mild hypoxia accelerates CCM disease by promoting angiogenesis, neuroinflammation, and vascular thrombosis in the brains of CCM mouse models. We used genetic studies, RNA sequencing, spatial transcriptome, micro-computed tomography, fluorescence-activated cell sorting, multiplex immunofluorescence, coculture studies, and imaging techniques to reveal that sustained mild hypoxia via the CX3CR1-CX3CL1 signaling pathway influences cell-specific neuroinflammatory interactions, contributing to heterogeneity in CCM severity. Histological and expression profiles of CCM neurovascular lesions (Slco1c1-iCreERT2;Pdcd10fl/fl; Pdcd10BECKO) in male and female mice found that sustained mild hypoxia (12% O2, 7 days) accelerates CCM disease. Our findings indicate that a small reduction in oxygen levels can significantly increase angiogenesis, neuroinflammation, and thrombosis in CCM disease by enhancing the interactions between endothelium, astrocytes, and immune cells. Our study indicates that the interactions between CX3CR1 and CX3CL1 are crucial in the maturation of CCM lesions and propensity to CCM immunothrombosis. In particular, this pathway regulates the recruitment and activation of microglia and other immune cells in CCM lesions, which leads to lesion growth and thrombosis. We found that human CX3CR1 variants are linked to lower lesion burden in familial CCMs, proving it is a genetic modifier in human disease and a potential marker for aggressiveness. Moreover, monoclonal blocking antibody against CX3CL1 or reducing 1 copy of the Cx3cr1 gene significantly reduces hypoxia-induced CCM immunothrombosis. Our study reveals that interactions between CX3CR1 and CX3CL1 can modify CCM neuropathology when lesions are accelerated by environmental hypoxia. Moreover, a hypoxic environment or hypoxia signaling caused by CCM disease influences the balance between neuroinflammation and neuroprotection mediated by CX3CR1-CX3CL1 signaling. These results establish CX3CR1 as a genetic marker for patient stratification and a potential predictor of CCM aggressiveness.

Report of a Novel KRIT1 Mutation in a Korean Family with Familial Cerebral Cavernous Malformation (S34.010)

Report of a Novel KRIT1 Mutation in a Korean Family with Familial Cerebral Cavernous Malformation (S34.010)

Deep-Learning Uncovers certain CCM Isoforms as Transcription Factors.

Cerebral Cavernous Malformations (CCMs) are brain vascular abnormalities associated with an increased risk of hemorrhagic strokes. Familial CCMs result from autosomal dominant inheritance involving three genes: KRIT1 (CCM1), MGC4607 (CCM2), and PDCD10 (CCM3). CCM1 and CCM3 form the CCM Signal Complex (CSC) by binding to CCM2. Both CCM1 and CCM2 exhibit cellular heterogeneity through multiple alternative spliced isoforms, where exons from the same gene combine in diverse ways, leading to varied mRNA transcripts. Additionally, both demonstrate nucleocytoplasmic shuttling between the nucleus and cytoplasm, suggesting their potential role in gene expression regulation as transcription factors (TFs). Due to the accumulated data indicating the cellular localization of CSC proteins in the nucleus and their interaction with progesterone receptors, which serve dual roles as both cellular signaling components and TFs, a question has arisen regarding whether CCMs could also function in both capacities like progesterone receptors. To investigate this potential, we employed our proprietary deep-learning (DL)-based algorithm, specifically utilizing a biased-Support Vector Machine (SVM) model, to explore the plausible cellular function of any of the CSC proteins, particularly focusing on CCM gene isoforms with nucleocytoplasmic shuttling, acting as TFs in gene expression regulation. Through a comparative DL-based predictive analysis, we have effectively discerned a collective of 11 isoforms across all CCM proteins (CCM1-3). Additionally, we have substantiated the TF functionality of 8 isoforms derived from CCM1 and CCM2 proteins, marking the inaugural identification of CCM isoforms in the role of TFs. This groundbreaking discovery directly challenges the prevailing paradigm, which predominantly emphasizes the involvement of CSC solely in endothelial cellular functions amid various potential cellular signal cascades during angiogenesis.

Patient-reported outcome measures in patients with familial cerebral cavernous malformations: results from the Treat_CCM trial.

The Phase 1/2 Treat_CCM randomized controlled trial for people with familial cerebral cavernous malformations (FCCMs) confirmed the safety of propranolol and suggested beneficial effects on intracerebral hemorrhage or new focal neurological deficits, but the effects on patient-reported outcome measures have not been reported. Participants completed self-reported questionnaires at baseline, 1 and 2 years. Depression was assessed with the Beck Depression Inventory-II (BDI-2); Anxiety with the State-Trait Anxiety Inventory X1 and X2 (STAI X-1 and STAI X-2); and Quality of Life with the Short Form 36 (SF-36), split into the physical and mental component scales (PCS and MCS). Differences between treatment groups and the general population were assessed. Change over time by treatment was assessed by means of mixed models. In total, 71 participants (48 propranolol and 23 standard care) were enrolled, of whom 61 (73%) completed questionnaires at baseline and 2-year FU. At baseline, no differences between treatment groups for any of the questionnaires were present. Twenty (31.7%) patients were considered depressed at baseline, while this proportion was lower in the propranolol group after 2 years (28.6% vs. 55.5%, p = 0.047). The STAI X-1 and X-2 scores were stable over time. PCS was lower in FCCM patients as compared with the general Italian population, while the MCS was similar to the general population. No effect of propranolol was found for both PCS and MCS. Depression is common among patients with FCCM. Patients randomized to propranolol had a lower proportion of participants with depression after 2 years.Clinical trial registration: https://clinicaltrials.gov/, identifier (NCT03589014).

Abstract TP11: Familial Cerebral Cavernous Malformations: Impact of Lesion Number and Size on Functional Status and Quality of Life

Introduction: Individuals with familial cerebral cavernous malformation (FCCM) syndrome may experience a wide variety of psychosocial challenges beyond the known neurologic sequelae of headache, seizure, and intracerebral hemorrhage. Little is known about how number and size of CCMs correlate with overall function and quality of life. This study aims to better characterize the impact of CCM burden on function and quality of life using a standardized metric. Methods: Patients with FCCM from four institutions were included for analysis. Functional status and quality of life were measured using the Neuro-QoL (available at www.NIHToolbox.org). Lesions were manually counted on brain MRI at time of enrollment; lesions ≥5mm were considered large lesions. Log-squared residuals were determined for each subject to adjust lesion count based on age and sex. Linear regression analysis was performed to assess association between adjusted number of lesions and Neuro-QoL scores. Results: 96 patients with FCCM were included from four organizations. FCCM genetic subtype was known in 59/96 (61%) of cases (CCM1: n= 53; CCM2: n=4; CCM3: n=2); the remainder were diagnosed based on clinical criteria. Median mRS was 1; 41% had experienced intracerebral hemorrhage. Increased number of lesions was associated with higher emotional dysregulation (p=0.045) and less positive affect (p=0.022). Increased number of large lesions was associated with increased stigma (p=0.033) and decreased social participation (p=0.041) and social satisfaction (p=0.031). Anxiety, depression, upper and lower extremity function, and cognition showed no significant association with number of lesions regardless of size. Conclusions: This study highlights that mood may be associated with number of CCM lesions and social participation may be associated with number of large lesions. Motor function and diagnoses of anxiety and depression showed no significant association with CCM burden. As treatments emerge for individuals with FCCM, metrics such as the Neuro-QoL allow for standardized measurement of impacts of treatments on patient-centric outcomes such as function and quality of life.

Abstract WP224: Association of Quality-of-Life Domains and Clinical Symptoms in Pediatric Cerebral Cavernous Malformation Patients

Introduction: Cerebral cavernous malformations (CCMs) in children are associated with focal seizures, intracranial hemorrhage, and neurologic deficits, impacting quality of life (QoL). However, previous studies have not evaluated the impact of CCMs on QoL domains in pediatric populations. Methods: Completed self-reports (n=16) or parent-proxy reports (n=32) measuring patient outcomes in physical, mental and social health domains were collected from 48 pediatric familial CCM patients (5-17 years) enrolled in the Brain Vascular Malformation Consortium (BVMC) CCM study between 2019-2022. Survey responses were converted into domain T-scores and standardized against a reference population (mean ( M )=50, SD=10). Scores were oriented for higher scores to reflect worse outcomes. One-sample t-tests analyzed whether mean T scores for each domain differed significantly from 50 (p<0.05). Multivariable linear regression tested whether PROMIS domain T scores were associated with (a) prior hemorrhage, (b) history of seizures, and (c) history of headaches, adjusting for age and sex. Standardized effect sizes were reported. Results: Compared to the reference population, pediatric CCM patients reported significantly better levels of mobility ( M= -2.47, 95% CI=-4.25 to -0.08; p=0.042), anxiety ( M =-4.66, 95% CI=-8.37 to -0.04, p=0.02), depression ( M= -6.13, 95% CI=-8.79 to -3.47, p<0.01), fatigue ( M = -7.40, 95% CI=-10.64 to -4.16, p<0.01), and pain (M =-6.71, 95% CI=-9.79 to -3.63, p<0.01). Multivariable linear regression showed that CCM patients with a history of headaches had impacted peer relationships compared to those without headaches, with an effect size of 7.86 (95% CI=0.162 to 15.55, p=0.05). Patients with a history of seizures reported higher pain scores compared to those without seizures, with an effect size of 5.58 (95% CI=-0.603 to 11.77, p=0.08). Conclusion: Psychological and social functioning domains, particularly experiences in pain and relationships, were impacted in the pediatric CCM population. Further studies conducted with larger sample sizes could determine if the PROMIS questionnaire can reliably assess patient or proxy-reported outcomes in the pediatric CCM population and evaluate within-person changes over time.

The familial cerebral cavernous malformation presented with facial paralysis

The familial cerebral cavernous malformation presented with facial paralysis

Clinical characteristics of familial and sporadic pediatric cerebral cavernous malformations and outcomes.

Cerebral cavernous malformation (CCM) is a subtype of the vascular malformations found within the cerebral cortex. Although rare and usually discovered incidentally, these vascular abnormalities can predispose patients to spontaneous cerebral hemorrhage and subsequently lead to a myriad of neurological symptoms at presentation such as seizures and other focal neurological deficits. Although the symptoms and presentations of CCM have been adequately described in the adult population, disease characteristics and outcomes have not been extensively described in the pediatric population. Furthermore, the etiology of CCM-e.g., familial versus sporadic disease, as well as the risk factors for hemorrhage and neurological deficits and predictors of clinical and surgical outcomes-has not been adequately explored in the pediatric population. The current study attempts to classify and characterize differences in the clinical presentation, characteristics, and outcomes of CCMs between familial and sporadic cases within the pediatric population. A retrospective review identified 131 pediatric patients with radiographically confirmed diagnosis of CCM. All pertinent demographic and clinical variables were collected. CCM lesions were characterized using T2-weighted and susceptibility-weighted angiography (SWAN) MRI. Statistical analysis was conducted using the t-test for continuous variables, whereas categorical variables were analyzed with the Fisher exact test or chi-square test. Multivariate analysis was performed using a Cox proportional hazards model with R version 4.2.0. This retrospective study identified 131 pediatric CCM patients with a mean age of 8.4 years, and 54% (n = 71) were male. Twenty-seven percent (n = 35) were identified as cases with familial CCM, with the remainder classified as sporadic. The most common symptoms at presentation included generalized symptoms (headaches, nausea, and vomiting) or seizures, with a large proportion of patients also presenting as asymptomatic. No significant differences were observed in severity of symptoms between patients harboring different forms of the disease. Patients with familial CCM were noted to have a larger lesion size on average (5.26 cm3 vs 1.6 cm3, p = 0.047). These patients also had a shorter progression-free follow-up interval, with 50% of patients showing progression by 888 days, compared with only 15% of sporadic CCM patients during the same period (p = 0.0019). Familial etiology of the disease and larger average lesion volume were independent, significant predictors of disease progression (p = 0.001, HR 3.29, 95% CI 1.65-6.54) and future hemorrhage (p = 0.023, HR 1.1, 95% CI 1.01-1.10), respectively. Familial and sporadic CCMs tend to present with similar characteristics within the pediatric population. Patients with the familial form of the disease have an increased risk of progressive disease in terms of further hemorrhagic events.

Towards a neurocognitive profile in familial cerebral cavernous malformations

BackgroundFamilial cerebral cavernous malformations (FCCM) is a rare autosomal dominant disease, characterized by vascular malformations that can lead to macro and microhemorrhages. The neurocognitive impact of FCCM is still underrecognized.MethodsWe report the clinical, neurocognitive, imaging and genetic data of a three generation family with FCCM.ResultsA 63-year-old man (proband) had progressive memory impairment since the last year. Neurologic exam was unremarkable. Brain MRI showed multiple large cavernomas (mainly in the pons, left temporal, and right temporo-parietal) and scattered microhemorrhages. Neuropsychological assessment mainly revealed left frontal and right temporo-parietal dysfunction. A 41-year-old daughter, presented with headache, vertigo and memory complaints in the last 2 years. Neurological examination revealed left central facial paralysis. Brain MRI showed two small right parietal and internal capsule cavernomas, as well as microhemorrhages. Neuropsychological assessment showed moderate temporal neocortical left dysfunction. A 34-year-old daughter had recurrent headache and memory complaints, with unremarkable neurological exam. Brain MRI revealed two large cavernomas (left fronto-orbitary and inferior temporal), with few microhemorrhages. Neuropsychological assessment was normal. A granddaughter had mild headaches and a small right cerebellar cavernoma, without microhemorrhages. Neuropsychological assessment showed mild temporal neocortical left dysfunction. A nonsense variant, c.55C > T; p.R19* generating a premature stop codon in CCM2 gene shared by all affected family members was identified.ConclusionsNeuropsychological evaluation showed that memory complaints and cognitive impairment could be an important unrecognized finding in FCCM. Its pathophysiological mechanisms are still unknown but the role of recurrent microhemorrhages could provide an interesting hypothesis.

Amplification of protease-activated receptors signaling in sporadic cerebral cavernous malformation endothelial cells.

In the central nervous system, thrombin-mediated activation of protease-activated receptors (PARs) results in neuroinflammation and increased vascular permeability. These events have been linked to cancer and neurodegeneration. Endothelial cells (ECs) isolated from sporadic cerebral cavernous malformation (CCM) specimens showed dysregulation of genes involved in "thrombin-mediated PAR-1 activation" signaling. CCM is a vascular disease involving brain capillaries. In CCM, ECs show defective cell junctions. Oxidative stress and neuroinflammation play a key role in disease onset and progression. In order to confirm the possible role of thrombin pathway in sporadic CCM pathogenesis, we evaluated PARs expression in CCM-ECs. We found that sporadic CCM-ECs overexpress PAR1, PAR3 and PAR4, together with other coagulation factor encoding genes. Moreover, we investigated about expression of the three familial CCM genes (KRIT1, CCM2 and PDCD10) in human cerebral microvascular ECs, following thrombin exposure, as well as protein level. Thrombin exposure affects EC viability and results in dysregulation of CCM gene expression and, then, in decreased protein level. Our results confirm amplification of PAR pathway in CCM suggesting, for the first time, the possible role of PAR1-mediated thrombin signaling in sporadic CCM. Thrombin-mediated PARs over activation results in increased blood-brain barrier permeability due to loss of cell junction integrity and, in this context, also the three familial CCM genes may be involved.

Molecular genetic features and clinical manifestations in Chinese familial cerebral cavernous malformation: from a novel KRIT1/CCM1 mutation (c.1119dupT) to an overall view.

Cerebral cavernous malformations (CCMs) are common vascular anomaly diseases in the central nervous system associated with seizures, cerebral microbleeds, or asymptomatic mostly. CCMs can be classified as sporadic or familial, with familial cerebral cavernous malformations (fCCMs) being the autosomal dominant manner with incomplete penetrance. Germline mutations of KRIT1, CCM2, and PDCD10 are associated with the pathogenesis of fCCMs. Till now, little is known about the fCCMs mutation spectrum in the Han Chinese population. In this study, we enrolled a large, aggregated family, 11/26 of the family members were diagnosed with CCMs by pathological or neuroradiological examination, with a high percentage (5/9) of focal spinal cord involvement. Genomic DNA sequencing verified a novel duplication mutation (c.1119dupT, p.L374Sfs*9) in exon 9 of the Krev interaction trapped 1 (KRIT1) gene. The mutation causes a frameshift and is predicted to generate a truncated KRIT1/CCM1 protein of 381 amino acids. All our findings confirm that c.1119dupT mutation of KRIT1 is associated with fCCMs, which enriched the CCM genes' mutational spectrum in the Chinese population and will be beneficial for deep insight into the pathogenesis of Chinese fCCMs. Additionally, with a retrospective study, we analyzed the molecular genetic features of Chinese fCCMs, most of the Chinese fCCMs variants are in the KRIT1 gene, and all these variants result in the functional deletion or insufficiency of the C-terminal FERM domain of the KRIT1 protein.

Familial CCM Genes Might Not Be Main Drivers for Pathogenesis of Sporadic CCMs-Genetic Similarity between Cancers and Vascular Malformations.

Cerebral cavernous malformations (CCMs) are abnormally dilated intracranial capillaries that form cerebrovascular lesions with a high risk of hemorrhagic stroke. Recently, several somatic "activating" gain-of-function (GOF) point mutations in PIK3CA (phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit p110α) were discovered as a dominant mutation in the lesions of sporadic forms of cerebral cavernous malformation (sCCM), raising the possibility that CCMs, like other types of vascular malformations, fall in the PIK3CA-related overgrowth spectrum (PROS). However, this possibility has been challenged with different interpretations. In this review, we will continue our efforts to expound the phenomenon of the coexistence of gain-of-function (GOF) point mutations in the PIK3CA gene and loss-of-function (LOF) mutations in CCM genes in the CCM lesions of sCCM and try to delineate the relationship between mutagenic events with CCM lesions in a temporospatial manner. Since GOF PIK3CA point mutations have been well studied in reproductive cancers, especially breast cancer as a driver oncogene, we will perform a comparative meta-analysis for GOF PIK3CA point mutations in an attempt to demonstrate the genetic similarities shared by both cancers and vascular anomalies.

Abstract WP18: Association Of Quality Of Life Domains And Clinical Symptoms In Familial Cerebral Cavernous Malformation Patients

Background: Familial cerebral cavernous malformation (FCCM) is characterized by multiple brain lesions at risk for intracranial hemorrhage (ICH) and neurological morbidity, affecting quality of life (QoL). PROMIS-29 is a QoL survey validated in some neurological diseases but has not yet been evaluated for FCCM. We aimed to assess whether PROMIS-29 health domains are associated with clinical symptoms in FCCM patients. Methods: PROMIS-29 surveys assessing seven QoL domains were completed by 198 FCCM patients >=18 years either at a baseline or follow-up visit in the Brain Vascular Malformation Consortium CCM study. Raw PROMIS-29 domain scores were converted to T scores that are standardized to a reference population with mean 50 and SD 10, and oriented so that higher scores are unfavorable. One-sample t-tests and p-values assessed whether mean T-scores were significantly different from 50 (p<0.05). Multivariable linear regression was used to test whether domain scores were associated with history of ICH, seizures, or headaches at time of survey, adjusting for age and sex. Results: Compared to a reference population, FCCM patients had significantly higher anxiety (52.7, 95% CI: 51.3-54.2, p<0.001), pain (52.5, 95% CI: 51.0-54.0, p=0.002), and physical functioning scores (52.0, 95% CI: 51.4-54.5, p<0.001), but lower social participation scores (46.9, 95% CI: 45.4-48.5, p<0.001). History of ICH and headaches were significantly associated with 4 domains each (all >3 points, p<0.05, Table), while seizures were not associated. Fatigue was the only affected domain in common. Conclusion: FCCM patients differed significantly from the reference population on anxiety, pain, physical functioning, and social participation domains. These same domains were significantly associated with history of ICH or headaches in patients. Further studies will determine whether changes in health domains are associated with changes in clinical symptoms.

Clinicoradiologic data of familial cerebral cavernous malformation with age-related disease burden.

Familial cerebral cavernous malformation (FCCM) is an autosomal dominant disease induced by loss-of-function mutations in three CCM genes, KRIT1, CCM2, and PDCD10. However, previous studies paid little attention to analyzing the radiologic features and age-related disease burden according to the genes. Therefore, we retrospectively reviewed the genetic tests of our center's clinical FCCM patients. This study investigated clinical FCCM patients with multiple lesions or a family history of CCMs who underwent the FCCM gene (KRTI1, CCM2, and PDCD10) panel test. The clinical, genetic, and radiologic features were analyzed. Among the patients (n=34) undergoing the FCCM gene test, twenty-seven patients had CCM confirmed by brain MRI, and twenty-one patients were considered to have FCCM (cohort 1). In cohort 1, thirteen patients had mutations in the FCCM gene, but eight did not. Cohort 2 comprised cohort 1 and four family members with the same mutation as the probands. Six novel variants in CCM genes were detected (KRIT1 c.22_26del, c.815dup, c.1094_1098del, c.1147-2A>G, c.2124dup, and PDCD10 c.150 + 1dup). Cohort 1 demonstrated that brainstem lesions were mostly associated with the mutation detection in CCM genes (brainstem, lateral temporal, and parietal lesions vs. lateral temporal and parietal lesions, AUC 0.928 vs. 0.779, P=0.0389). The radiologic severity worsened according to age in the KRIT1 group compared with the Mutation not detected group (correlation coefficient 0.75 (P < 0.001) versus 0.53 (P=0.004)). The brainstem lesion could be the radiologic marker for FCCM with the mutation detected. The age-related disease burden regarding FCCM according to genetic information was demonstrated.

Monogenic Causes in Familial Stroke Across Intracerebral Hemorrhage and Ischemic Stroke Subtypes Identified by Whole-Exome Sequencing

Whole exome sequencing (WES) has been used to detect rare causative variants in neurological diseases. However, the efficacy of WES in genetic diagnosis of clinically heterogeneous familial stroke remains inconclusive. We prospectively searched for disease-causing variants in unrelated probands with defined familial stroke by candidate gene/hotspot screening and/or WES, depending on stroke subtypes and neuroimaging features at a referral center. The clinical significance of each variant was determined according to the American College of Medical Genetics guidelines. Among 161 probands (mean age at onset 53.2 ± 13.7 years; male 63.4%), 33 participants (20.5%) had been identified with 19 pathogenic/likely pathogenic variants (PVs; WES applied 152/161 = 94.4%). Across subtypes, the highest hit rate (HR) was intracerebral hemorrhage (ICH, 7/18 = 38.9%), particularly with the etiological subtype of structural vasculopathy (4/4 = 100%, PVs in ENG, KRIT1, PKD1, RNF213); followed by ischemic small vessel disease (SVD, 15/48 = 31.3%; PVs in NOTCH3, HTRA1, HBB). In contrast, large artery atherosclerosis (LAA, 4/44 = 9.1%) and cardioembolism (0/11 = 0%) had the lowest HR. NOTCH3 was the most common causative gene (16/161 = 9.9%), presenting with multiple subtypes of SVD (n = 13), ICH (n = 2), or LAA (n = 1). Importantly, we disclosed two previously unreported PVs, KRIT1 p.E379* in a familial cerebral cavernous malformation, and F2 p.F382L in a familial cerebral venous sinus thrombosis. The contribution of monogenic etiologies was particularly high in familial ICH and SVD subtypes in our Taiwanese cohort. Utilizing subtype-guided hotspot screening and/or subsequent WES, we unraveled monogenic causes in 20.5% familial stroke probands, including 1.2% novel PVs. Genetic diagnosis may enable early diagnosis, management and lifestyle modification.Graphical Among 161 familial stroke probands, 33 (20.5%) had been identified pathogenic or likely pathogenic monogenic variants related to stroke. The positive hit rate among all subtypes was high in intracerebral hemorrhage (ICH) and ischemic small vessel disease (SVD). Notably, two previously unreported variants, KRIT1 p.E379* in a familial cerebral cavernous malformation and F2 p.F382L in familial cerebral venous sinus thrombosis, were disclosed. CVT cerebral venous thrombosis; HTN Hypertensive subtype; LAA large artery atherosclerosis; SV structural vasculopathy; U Undetermined.

Cas9-Mediated Nanopore Sequencing Enables Precise Characterization of Structural Variants in CCM Genes.

Deletions in the CCM1, CCM2, and CCM3 genes are a common cause of familial cerebral cavernous malformations (CCMs). In current molecular genetic laboratories, targeted next-generation sequencing or multiplex ligation-dependent probe amplification are mostly used to identify copy number variants (CNVs). However, both techniques are limited in their ability to specify the breakpoints of CNVs and identify complex structural variants (SVs). To overcome these constraints, we established a targeted Cas9-mediated nanopore sequencing approach for CNV detection with single nucleotide resolution. Using a MinION device, we achieved complete coverage for the CCM genes and determined the exact size of CNVs in positive controls. Long-read sequencing for a CCM1 and CCM2 CNV revealed that the adjacent ANKIB1 and NACAD genes were also partially or completely deleted. In addition, an interchromosomal insertion and an inversion in CCM2 were reliably re-identified by long-read sequencing. The refinement of CNV breakpoints by long-read sequencing enabled fast and inexpensive PCR-based variant confirmation, which is highly desirable to reduce costs in subsequent family analyses. In conclusion, Cas9-mediated nanopore sequencing is a cost-effective and flexible tool for molecular genetic diagnostics which can be easily adapted to various target regions.

Safety and efficacy of propranolol for treatment of familial cerebral cavernous malformations (Treat_CCM): a randomised, open-label, blinded-endpoint, phase 2 pilot trial

Observations in people with cerebral cavernous malformations, and in preclinical models of this disorder, suggest that the β-blocker propranolol might reduce the risk of intracerebral haemorrhage. We aimed to evaluate the safety and efficacy of prolonged treatment with propranolol to reduce the incidence of symptomatic intracerebral haemorrhage or focal neurological deficit in people with familial cerebral cavernous malformations. We conducted a randomised, open-label, blinded-endpoint, phase 2 pilot trial (Treat_CCM) at six national reference centres for rare diseases in Italy. People aged 18 years or older with symptomatic familial cerebral cavernous malformation were eligible for enrolment. Participants were randomly assigned (2:1) to receive either oral propranolol (20-320 mg daily) plus standard care (intervention group), or standard care alone (control group), for 24 months. Participants, caregivers, and investigators were aware of treatment group assignment. Participants had clinical assessments and 3 T brain MRI at baseline and at 12 and 24 months. The primary outcome was new occurrence of symptomatic intracerebral haemorrhage or focal neurological deficit attributable to cerebral cavernous malformation over 24 months. Outcome assessors were masked to treatment group assignment. The primary analysis was done in the intention-to-treat population. Because of the pilot study design, we chose a one-sided 80% CI, which could either exclude a clinically meaningful effect or show a signal of efficacy. This trial is registered with EudraCT, 2017-003595-30, and ClinicalTrials.gov, NCT03589014, and is closed to recruitment. Between April 11, 2018, and Dec 5, 2019, 95 people were assessed for eligibility and 83 were enrolled, of whom 57 were assigned to the propranolol plus standard care group and 26 to the standard care alone group. The mean age of participants was 46 years (SD 15); 48 (58%) were female and 35 (42%) were male. The incidence of symptomatic intracerebral haemorrhage or focal neurological deficit was 1·7 (95% CI 1·4-2·0) cases per 100 person-years (two [4%] of 57 participants) in the propranolol plus standard care group and 3·9 (3·1-4·7) per 100 person-years (two [8%] of 26) in the standard care alone group (univariable hazard ratio [HR] 0·43, 80% CI 0·18-0·98). The univariable HR showed a signal of efficacy, according to predefined criteria. The incidence of hospitalisation did not differ between groups (8·2 cases [95% CI 7·5-8·9] per 100 person-years in the propranolol plus standard care group vs 8·2 [95% CI 7·1-9·3] per 100 person-years in the standard care alone group). One participant in the standard care alone group died of sepsis. Three participants in the propranolol plus standard care group discontinued propranolol due to side-effects (two reported hypotension and one reported weakness). Propranolol was safe and well tolerated in this population. Propranolol might be beneficial for reducing the incidence of clinical events in people with symptomatic familial cerebral cavernous malformations, although this trial was not designed to be adequately powered to investigate efficacy. A definitive phase 3 trial of propranolol in people with symptomatic familial cerebral cavernous malformations is justified. Italian Medicines Agency, Associazione Italiana per la Ricerca sul Cancro, Swedish Science Council, Knut and Alice Wallenberg Foundation, CARIPLO Foundation, Italian Ministry of Health.

INNV-05. CO-OCCURRENCES OF A HIGH-GRADE GLIOMA WITH CAVERNOUS MALFORMATIONS AND PATHOGENIC VARIANTS IN PDCD10 AND SMARCA4

Abstract INTRODUCTION The co-occurrence of multiple disease processes can make for more challenging diagnoses. Here we report an unusual case of a patient found to have an IDH1-mutant high-grade glioma along with multiple cerebral cavernous malformations and pathogenic germline variants in PDCD10 and SMARCA4. Case Description: A 17-year-old female presented with left arm paresthesia and weakness along with persistent headaches within the frontal and occipital regions that progressed in intensity to include nausea and emesis. A fast sequence magnetic resonance imaging (MRI) of her head was obtained that revealed the presence of multiple bilateral cystic lesions suspicious for cavernomas with the most notable lesion in the right parietal lobe. Ophthalmology consultation revealed grade III papilledema bilaterally. A full brain MRI with and without contrast was obtained and demonstrated a right anterior parietal lobe lesion with associated mass effect, as well as multiple bilateral supratentorial and left cerebellar cavernous malformations. The patient underwent tumor debulking of her dominant lesion. Pathology revealed an IDH1 mutant diffuse astrocytoma, WHO grade 3. Germline genetic testing was pursued which revealed a PDCD10 pathogenic variant consistent with familial cerebral cavernous malformation syndrome and a likely pathogenic variant in SMARCA4. Treatment of her high-grade-glioma included radiation therapy followed by maintenance oral temozolomide. DISCUSSION This case illustrates the unusual co-occurrences of a high-grade glioma with familial cavernous malformation syndrome and germline pathogenic variants in PDCD10 and SMARCA4. Our patient continues to do well clinically, but because of her now significant risk of developing ovarian cancer she has elected to undergo a prophylactic bilateral salpingo-oophorectomy. Recognition of abnormal genetic results is critical in the setting of multiple disease processes and can play a crucial role in the on-going care for a patient.

Natural history of familial cerebral cavernous malformation syndrome in children: a multicenter cohort study

PurposeThere is limited data concerning neuroimaging findings and longitudinal evaluation of familial cerebral cavernous malformations (FCCM) in children. Our aim was to study the natural history of pediatric FCCM, with an emphasis on symptomatic hemorrhagic events and associated clinical and imaging risk factors.MethodsWe retrospectively reviewed all children diagnosed with FCCM in four tertiary pediatric hospitals between January 2010 and March 2022. Subjects with first available brain MRI and ge 3 months of clinical follow-up were included. Neuroimaging studies were reviewed, and clinical data collected. Annual symptomatic hemorrhage risk rates and cumulative risks were calculated using survival analysis and predictors of symptomatic hemorrhagic identified using regression analysis.ResultsForty-one children (53.7% males) were included, of whom 15 (36.3%) presenting with symptomatic hemorrhage. Seven symptomatic hemorrhages occurred during 140.5 person-years of follow-up, yielding a 5-year annual hemorrhage rate of 5.0% per person-year. The 1-, 2-, and 5-year cumulative risks of symptomatic hemorrhage were 7.3%, 14.6%, and 17.1%, respectively. The latter was higher in children with prior symptomatic hemorrhage (33.3%), CCM2 genotype (33.3%), and positive family history (20.7%). Number of brainstem (adjusted hazard ratio [HR] = 1.37, P = 0.005) and posterior fossa (adjusted HR = 1.64, P = 0.004) CCM at first brain MRI were significant independent predictors of prospective symptomatic hemorrhage.ConclusionThe 5-year annual and cumulative symptomatic hemorrhagic risk in our pediatric FCCM cohort equals the overall risk described in children and adults with all types of CCM. Imaging features at first brain MRI may help to predict potential symptomatic hemorrhage at 5-year follow-up.