RNF213 rs112735431 polymorphism in intracranial artery steno-occlusive disease and moyamoya disease in Koreans

FOXM1 c.1205 C > A mutation is associated with unilateral Moyamoya disease and inhibits angiogenesis in human brain endothelial cells

Unilateral moyamoya disease (MMD) represents a distinct subtype characterised by occlusive changes in the circle of Willis and abnormal vascular network formation. However, the aetiology and pathogenesis of unilateral MMD remain unclear. In this study, genetic screening of a family with unilateral MMD using whole-genome sequencing helped identify the c.1205 C > A variant of FOXM1, which encodes the transcription factor FOXM1 and plays a crucial role in angiogenesis and cell proliferation, as a susceptibility gene mutation. We demonstrated that this mutation significantly attenuated the proangiogenic effects of FOXM1 in human brain endothelial cells, leading to reduced proliferation, migration, and tube formation. Furthermore, FOXM1 c.1205 C > A results in increased apoptosis of human brain endothelial cells, mediated by the downregulation of the transcription of the apoptosis-inhibiting protein BCL2. These results suggest a potential role for the FOXM1 c.1205 C > A mutation in the pathogenesis of unilateral MMD and may contribute to the understanding and treatment of this condition.

RNF213 in moyamoya disease: Genotype-phenotype association and the underlying mechanism

ABSTRACT

Moyamoya disease (MMD) is a cerebrovascular disorder characterized by a steno-occlusive internal carotid artery and compensatory vascular network formation. Although the precise pathogenic mechanism remains elusive, genetic association studies have identified RNF213 as the principal susceptibility gene for MMD, with the single nucleotide polymorphism p.R4810K recognized as the founder variant predominantly in the Asian populations. Distinct genotype-phenotype correlations are observable in RNF213-related MMD. The clinical manifestations linked to p.R4810K bear commonalities within Asian cohort, including familial predisposition, earlier age of onset, ischemic episodes, and involvement of the posterior cerebral artery (PCA). However, despite these shared phenotypic characteristics, there is significant heterogeneity in RNF213-related MMD presentations. This diversity manifests as variations across ethnic groups, inconsistent clinical symptoms and prognosis, and occurrence of other vasculopathies involving RNF213. This heterogeneity, in conjunction with the observed low disease penetrance of RNF213 mutations, suggests that the presence of these mutations may not be sufficient to cause MMD, underscoring the potential influence of other genetic or environmental factors. Although the current research might not have fully identified these additional contributors, experimental evidence points toward the involvement of RNF213 in angiogenesis, lipid metabolism, and the immune response. Future research is required to unveil the molecular mechanisms and identify the factors that synergize with RNF213 in the pathogenesis of MMD.

Fatal brainstem injury following proton radiation in a patient with medulloblastoma and a germline variant in RNF213

Brainstem injury occurs secondary to radiation to the posterior fossa in up to 2% of pediatric patients. It may occur after months to years after treatment. It has been associated with age less than 5 years and with comorbid conditions such as cerebrovascular disease, diabetes mellitus, and hypertension. Radiation necrosis is often symptomatic and can be fatal. A pathogenic variant in RNF213 was found in a patient who suffered fatal radiation necrosis. This mutation has been associated with moyamoya disease and may predispose to radiation necrosis.

Detailed phenotype of RNF213 p.R4810K variant identified by the Chinese patients with acute ischaemic stroke or transient ischaemic attack

BACKGROUND AND PURPOSE

The ring finger protein 213 gene (RNF213) p.R4810K variant increased the risk of acute ischaemic stroke (AIS) attributable to intracranial arterial stenosis (ICAS) in the Japanese and Korean populations. In this study, we aimed to examine the prevalence of the RNF213 p.R4810K variant in Chinese patients with AIS or transient ischaemic attack and identify the phenotype of the carriers.

METHODS

We analysed data from the Third China National Stroke Registry. All included participants were divided into two groups by carrier status of the p.R4810K variant. The aetiological classification was conducted according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. The presence of ICAS and extracranial arterial stenosis (ECAS) was defined as 50%-99% stenosis or occlusion of any intracranial and extracranial artery. Logistic regression models and Cox regression models were used to evaluate the association of the p.R4810K variant with TOAST classification, stenosis phenotypes and clinical outcomes.

RESULTS

A total of 10 381 patients were enrolled, among which 56 (0.5%) had the heterozygote GA genotype for p.R4810K. The variant carriers were younger (p=0.01), and more likely to suffer from peripheral vascular disease (p=0.04). The p.R4810K variant was associated with large-artery atherosclerosis (LAA) (adjusted OR=1.94, 95% CI 1.13 to 3.33), anterior circulation stenosis (adjusted OR=2.12, 95% CI 1.23 to 3.65) and ECAS (adjusted OR=2.29, 95% CI 1.16 to 4.51). Nevertheless, the p.R4810K variant was not associated with recurrence, poor functional outcome and mortality at 3 months and 1 year.

CONCLUSIONS

The RNF213 p.R4810K variant was associated with LAA, anterior circulation stenosis and ECAS in Chinese patients. Given the low carrying rate and only 1-year follow-up information, caution should be taken to interpret our findings in no statistically significant association between the p.R4810K variant and stroke prognosis in Chinese patients.

Meta-analysis of the association between RNF213 polymorphisms and clinical features of moyamoya disease in Asian population

BACKGROUND

We performed this study to explore the relationship between ring finger protein 213 (RNF213) gene polymorphisms and clinical features in moyamoya disease (MMD).

METHODS

Electronic databases (PubMed, Google Scholar, Embase, Scopus, Cochrane Library) were conducted from inception to May 15th, 2022. Odds ratios (ORs) with 95 % confidence intervals (CIs) were generated as effect size for binary variants. Subgroup analyses were performed by the RNF213 polymorphisms. Sensitivity was used to examine the robustness of associations.

RESULTS

A total of 16 articles and 3061 MMD patients were included and the association of five RNF213 polymorphisms on 9 clinical features of MMD were identified. Patients under 18 years of age at onset, familial MMD, cerebral ischemic stroke and posterior cerebral artery involvement (PCi) were significantly more common in mutant type compared with wild type of RNF213. Compared with each wild type, subgroup analysis showed that rs11273543 and rs9916351 remarkably increased risk of MMD on early onset, but rs371441113 evidently delayed the onset of MMD. Rs112735431 in mutant type was significantly higher than wild type in patients with PCi. Subgroup analysis in mutant type showed that rs112735431 conspicuously decreased intracerebral/ intraventricular hemorrhage (ICH/IVH) risk and yet rs148731719 obviously increased the risk in ICH/IVH.

CONCLUSION

More attention should be paid to patients on whom the ischemic MMD occurs younger than 18 years old. RNF213 polymorphism screening and cerebrovascular imaging examination should be performed to evaluate intracranial vascular involvement, to achieve early detection and early treatment and avoid more serious cerebrovascular events.

Physiological and pathophysiological mechanisms of the molecular and cellular biology of angiogenesis and inflammation in moyamoya angiopathy and related vascular diseases

Rationale

The etiology and pathophysiological mechanisms of moyamoya angiopathy (MMA) remain largely unknown. MMA is a progressive, occlusive cerebrovascular disorder characterized by recurrent ischemic and hemorrhagic strokes; with compensatory formation of an abnormal network of perforating blood vessels that creates a collateral circulation; and by aberrant angiogenesis at the base of the brain. Imbalance of angiogenic and vasculogenic mechanisms has been proposed as a potential cause of MMA. Moyamoya vessels suggest that aberrant angiogenic, arteriogenic, and vasculogenic processes may be involved in the pathophysiology of MMA. Circulating endothelial progenitor cells have been hypothesized to contribute to vascular remodeling in MMA. MMA is associated with increased expression of angiogenic factors and proinflammatory molecules. Systemic inflammation may be related to MMA pathogenesis.

Objective

This literature review describes the molecular mechanisms associated with cerebrovascular dysfunction, aberrant angiogenesis, and inflammation in MMA and related cerebrovascular diseases along with treatment strategies and future research perspectives.

Methods and results

References were identified through a systematic computerized search of the medical literature from January 1, 1983, through July 29, 2022, using the PubMed, EMBASE, BIOSIS Previews, CNKI, ISI web of science, and Medline databases and various combinations of the keywords "moyamoya," "angiogenesis," "anastomotic network," "molecular mechanism," "physiology," "pathophysiology," "pathogenesis," "biomarker," "genetics," "signaling pathway," "blood-brain barrier," "endothelial progenitor cells," "endothelial function," "inflammation," "intracranial hemorrhage," and "stroke." Relevant articles and supplemental basic science articles almost exclusively published in English were included. Review of the reference lists of relevant publications for additional sources resulted in 350 publications which met the study inclusion criteria. Detection of growth factors, chemokines, and cytokines in MMA patients suggests the hypothesis of aberrant angiogenesis being involved in MMA pathogenesis. It remains to be ascertained whether these findings are consequences of MMA or are etiological factors of MMA.

Conclusions

MMA is a heterogeneous disorder, comprising various genotypes and phenotypes, with a complex pathophysiology. Additional research may advance our understanding of the pathophysiology involved in aberrant angiogenesis, arterial stenosis, and the formation of moyamoya collaterals and anastomotic networks. Future research will benefit from researching molecular pathophysiologic mechanisms and the correlation of clinical and basic research results.

Validation and Extension Study Exploring the Role of RNF213 p.R4810K in 2,877 Chinese Moyamoya Disease Patients

OBJECTIVE

To validate, update, and extend the role of RNF213 p.R4810K (G>A) for predicting the phenotype of moyamoya disease (MMD) patients and explore the different effects on pediatric and adult groups.

METHODS

A total of 2,877 patients conducted from 2004 to 2018 were included. Review Manage 5.3 and SPSS 20.0 were applied to complete all statistical analyses. Information on age at onset, sex, initial symptom, family history and complications were obtained via retrospective chart review. Angiographic records were evaluated.

RESULTS

In China, geographic proximity to Korea or Japan may affect the carrying rate of RNF213 p.R4810K. The proportion of patients with the following characteristics was significantly higher (P <0.017) in the GA than in the GG group: female, age at onset < 18 years, infarct after transient ischemic attack, family history of MMD, and posterior cerebral artery involvement. For pediatric patients, GA showed more cerebral hemorrhage (CH) (odds ratios (ORs) [95% confidence intervals (CIs)] = 3.99 (1.61-9.88), P = 0.003), more patients were in the Suzuki early and intermediate stage (P = 0.001; P = 0.001, respectively), while for the adult group, GA indicated more female (OR [95% CIs] = 1.43 [1.15-1.79], P = 0.001), fewer patients with diabetes (0.58 [0.38-0.86], P = 0.007) and intermediate Suzuki stage (P = 3.70 × 10^-4).

CONCLUSIONS

The incidence and carrying rates of RNF213 p.R4810K in various regions for Chinese MMD patients were obviously different. RNF213 p.R4810K has different predictive effects on phenotypes of pediatric and adult patients.

RNF213 gene silencing upregulates transforming growth factor β1 expression in bone marrow-derived mesenchymal stem cells and is involved in the onset of Moyamoya disease

Moyamoya disease (MMD) is a chronic and progressive cerebrovascular occlusion disease, the precise etiology of which is poorly understood. Ring finger protein 213 (RNF213) has been previously identified as a susceptibility gene that serves an important role in angiogenesis, where it has been shown to be closely associated with the onset of MMD. Patients with MMD exhibit increased expression levels of various pro-inflammatory molecules and angiogenic factors. Under certain conditions, bone marrow mesenchymal stem cells (BMSCs) have the ability to differentiate to form neuron-like and microglia-like cells. In the present study, a total of 40 MMD patients and 40 healthy individuals were enrolled. ELISA assays revealed that the expression of serum vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGF-β1) were higher than that in healthy controls. Furthermore, rat BMSCs (rBMSCs) were isolated and cultured using the whole bone marrow adherence method, which were then phenotyped using flow cytometry. Osteogenic and adipogenic differentiation were determined by using Alizarin red and oil red O staining, respectively. RNF213 was knocked-down using a lentivirus-mediated short hairpin RNA system in passage three rBMSCs, and successful transfection of the RNF213 was confirmed by RT-qPCR and fluorescence imaging. The expression levels of VEGF and TGF-β1 in these rBMSCs were measured on days 7 and 14, respectively. The results demonstrated that RNF213 knockdown upregulated TGF-β1 at both protein and mRNA levels, but did not exert any effect on VEGF gene expression. In conclusion, these findings suggested that that RNF213 knockdown may contribute to aberrant TGF-β1 expression via a pathway that remains to be unidentified, indicating that quantitative changes in RNF213 gene expression may serve an important role in the pathogenesis of MMD.

Differences in Clinical Features among Different Onset Patterns in Moyamoya Disease

Moyamoya disease is characterized by severe stenosis at the ends of the bilateral internal carotid arteries and the development of collateral circulation. The disease is very diverse in terms of age at onset, onset patterns, radiological findings, and genetic phenotypes. The pattern of onset is mainly divided into ischemic and hemorrhagic onsets. Recently, the opportunity to identify asymptomatic moyamoya disease, which sometimes manifests as nonspecific symptoms such as headache and dizziness, through screening with magnetic resonance imaging has been increasing. Various recent reports have investigated the associations between the clinical features of different onset patterns of moyamoya disease and the corresponding imaging characteristics. In this article, we have reviewed the natural history, clinical features, and imaging features of each onset pattern of moyamoya disease.

Meta-analysis of genotype and phenotype studies to confirm the predictive role of the RNF213 p.R4810K variant for moyamoya disease

BACKGROUND AND PURPOSE

The aim of this meta-analysis study was to assess the predictive effects of RNF213 p.R4810K on phenotype in moyamoya disease (MMD).

METHODS

Electronic databases (e.g., Pubmed and EMBASE) were searched, and relevant articles published up to August 2020 were retrieved. Review Manager 5.3 and Stata 12.0 were used for all statistical analyses. Pooled odds ratios, with 95% confidence intervals, and three comparison models were evaluated to analyze the association between RNF213 pR4810K variant and clinical characteristics of MMD patients using a fixed-effects model.

RESULTS

A total of 2798 patients with MMD were selected and the effects of the heterozygous or homozygous RNF213 p.R4810K variant on 18 clinical features were identified. There were more patients aged <15 years in the GA and AA groups (AA vs GA: p = 0.009; AA vs GG: p = 0.003; GA vs GG: p = 0.001). Among homozygous patients, the majority experienced MMD onset before the age of 4 years (AA vs. GA: p < 0.00001; AA vs GG: p < 0.00001). The frequency of infarctions and transient ischemic attack was significantly higher in homozygotes and heterozygotes，respectively. However, the frequency of intracerebral/intraventricular hemorrhage was lower in patients with the GA than the GG genotype. More MMD patients with AA and GA genotypes had a family history of the disease (p = 0.003, p < 0.00001, respectively). Posterior cerebral artery involvement was more common in patients with the GA genotype (p < 0.00001).

CONCLUSION

The homozygous or heterozygous RNF213 variant may be an efficient biomarker with which to classify different clinical phenotypes of MMD.

Identification of Genetic Factors Underlying the Association between Sodium Intake Habits and Hypertension Risk

The role of sodium in hypertension remains unresolved. Although genetic factors have a significant impact on high blood pressure, studies comparing genetic susceptibility between people with low and high sodium diets are lacking. We aimed to investigate the genetic variations related to hypertension according to sodium intake habits in a large Korean population-based study. Data for a total of 57,363 participants in the Korean Genome and Epidemiology Study Health Examination were analyzed. Sodium intake was measured by a semi-quantitative food frequency questionnaire. We classified participants according to sodium intake being less than or greater than 2 g/day. We used logistic regression to test single-marker variants for genetic association with a diagnosis of hypertension, adjusting for age, sex, body mass index, exercise, alcohol, smoking, potassium intake, principal components 1, and principal components 2. Significant associations were defined as p < 5 × 10-8. In participants whose sodium intake was greater than 2 g/day, chromosome 6 open reading frame 10 (C6orf10)-human leukocyte antigen (HLA)-DQB1 rs6913309, ring finger protein (RNF)213 rs112735431, glycosylphosphatidylinositol anchored molecule-like (GML)- cytochrome P450 family 11 subfamily B member 1(CYP11B1) rs3819496, myosin light chain 2 (MYL2)-cut like homeobox 2 (CUX2) rs12229654, and jagged1 (JAG1) rs1887320 were significantly associated with hypertension. In participants whose intake was less than 2 g/day, echinoderm microtubule-associated protein-like 6(EML6) rs67617923 was significantly associated with hypertension. Genetic susceptibility associated with hypertension differed according to sodium intake. Identifying gene variants that contribute to the dependence of hypertension on sodium intake status could make possible more individualized nutritional recommendations for preventing cardiovascular diseases.

Association of Genetic Variants With Moyamoya Disease in 13 000 Individuals: A Meta-Analysis

Background and Purpose- A growing body of evidence indicates genetic components play critical roles in moyamoya disease (MMD). Firm conclusions from studies of this disease have been stymied by small sample sizes and a lack of replicative results. This meta-analysis was conducted to determine whether these genetic polymorphisms are associated with MMD. Methods- PubMed, Google Scholar, Embase, Wanfang, Web of Science, and China National Knowledge Infrastructure databases were used to identify potentially relevant studies published until January 2020. The Review Manager 5.2 and Stata 15.0 software programs were used to perform the statistical analysis. Heterogeneity was assessed using the Cochran Q test and quantified using the I² test. Results- Four thousand seven hundred eleven MMD cases and 8704 controls in 24 studies were included, evaluating 7 polymorphisms in 6 genes. The fixed-effect odds ratios (95% CI) in allelic model of MMP-2 rs243865 were 0.60 (0.41-0.88) (P=0.008). In the country-based subgroup analysis, the fixed-effect odds ratios (95% CI) of RNF213 rs112735431 in allelic model were China, 39.74 (26.63-59.31), Japan, 74.65 (42.79-130.24) and Korea, 50.04 (28.83-86.88; all P<0.00001). In the sensitivity analysis, the fixed-effect odds ratios (95% CI) of allelic and dominant models were the RNF213 rs148731719 variant, 2.17 (1.36-3.48; P=0.001), 2.20 (1.35-3.61; P=0.002), the TIMP-2 rs8179090 variant, 0.33 (0.25-0.43; P<0.00001), 0.88 (0.65-1.21; P=0.440) and the MMP-3 rs3025058 variant, 0.61 (0.47-0.79; P=0.0002), 0.55 (0.41-0.75; P=0.0001), respectively. Conclusions- RNF213 rs112735431 and rs148731719 were positively, and TIMP-2 rs8179090, MMP-2 rs243865, and MMP-3 rs3025058 were inversely associated with MMD using multiple pathophysiologic pathways. Studies in larger population should be conducted to clarify whether and how these variants are associated with MMD.

Distribution of Intracranial Major Artery Stenosis/Occlusion According to RNF213 Polymorphisms

Intracranial major artery stenosis/occlusion (ICASO) is the major cause of ischemic stroke. Recent studies have suggested that variants of RNF213, a susceptibility gene for moyamoya disease (MMD), are also related to non-MMD ICASO. Regarding the predominant involvement of steno-occlusion on anterior circulation in MMD, we hypothesized that the ICASO distribution pattern (anterior/posterior) in non-MMD may differ according to RNF213 variants. This study analyzed 1024 consecutive Korean subjects without MMD who underwent computed tomography angiography (CTA) or magnetic resonance angiography (MRA). We evaluated four single nucleotide polymorphisms (SNPs) in the exon region of RNF213: 4448G > A (rs148731719), 4810G > A (rs112735431), 4863G > A (rs760732823), and 4950G > A (rs371441113). Associations between RNF213 variants and anterior/posterior ICASO were examined using multivariate logistic regression analysis. Anterior ICASO was present in 23.0% of study subjects, and posterior ICASO was present in 8.2%. The GA genotype of RNF213 4810G > A (adjusted odds ratio (AOR) [95% confidence interval (CI)], 2.39 [1.14-4.87] compared to GG; p = 0.018) and GA genotype of RNF213 4950G > A (AOR [95% CI], 1.71 [1.11-2.63] compared to GG; p = 0.015) were more frequent in subjects with anterior ICASO. The genotype frequency of RNF213 4863G > A differed significantly according to the presence of posterior ICASO. Further investigations of the functional and biological roles of RNF213 will improve our understanding of the pathomechanisms of ICASO and cerebrovascular disease.

Prevalence of RNF213 variants in symptomatic intracranial arterial stenosis/occlusion in China

The ring finger protein 213 gene (RNF213) rs112735431 was significantly associated with intracranial artery stenosis/occlusion disease (ICASO) in Japan and Korea and to a lesser degree in China. We conducted a case-control study to examine the prevalence and correlates of the RNF213 rare variants in Chinese patients with symptomatic ICASO. A total of 503 cases including 390 ischemic stroke patients (ICASO-IS), 113 intracranial hemorrhage patients (ICASO-ICH) and 227 control subjects were recruited. The snapshot technique was used for RNF213 rare variants analysis, including rs112735431, rs148731719, rs37144111 and rs138130613. Moreover, a meta-analysis was performed to explore the relationship between RNF213 variants and ICASO in Asian. In our case-control study, we found that the rs138130613 variant was significantly associated with ICASO-IS (OR = 9.92, 95% CI 1.24-79.19, p = 0.03). The mean age of first ischemic stroke onset of variant carriers was earlier than the noncarriers (51.3 ± 18.0 versus 66.0 ± 12.9 years old, p = 0.02), but the conventional atherosclerotic risk factors and the characteristics of artery stenosis did not differ between them. In addition, the meta-analysis showed significant association between the rs112735431 polymorphism and the ICASO or ICASO-IS, and this variant was found more often in women and young-onset patients in Asia. This study suggests that the RNF213 rs112735431 and rs138130613 are genetic risk variants for ischemic stroke with intracranial artery stenosis/occlusion in China and rs112735431 is also associated with the high risk of ICASO in Asia. Further large-scale investigation of the RNF213 gene will provide new insights into pathogenetic mechanisms of symptomatic ICASO.

Association between ELP4 rs986527 polymorphism and the occurrence and development of intracranial arachnoid cyst

OBJECTIVE

The association between ELP4 rs986527 polymorphism and the occurrence and development of intracranial arachnoid cyst was studied in this paper.

METHODS

Eighty-five patients diagnosed with intracranial arachnoid cysts by cerebral computed tomography scan were selected. Sixty-three healthy volunteers for medical examination in hospitals served as controls. The cognition, depressive symptoms, and the likelihood of headache, dizziness, head trauma history, dementia, depression, and epilepsy were assessed. ELP4 genotypes and its allele frequency were determined by PCR, endonuclease restriction analysis, and gel electrophoresis.

RESULTS

ELP4 rs986527 had three genotypes: TT, TC, and CC. The intracranial arachnoid cyst group showed no statistically significant difference in genotype frequencies compared with healthy controls. There was no significant correlation between ELP4 rs986527 polymorphism and location of intracranial arachnoid cyst. TC and C genotype frequencies were associated with a higher incidence of clinical symptoms than TT genotype frequencies, and C allele frequencies were associated with a significantly higher incidence of clinical symptoms compared with T allele frequencies. There was no significant difference in TNF-α and IL-1β levels between TT/TC/CC genotypes before treatment. After treatment, the levels of TNF-α and IL-1β were significantly decreased in different genotypes, and the decrease in CC was the greatest. The frequency of TT and TC genotypes was higher than that of CC genotypes.

CONCLUSION

ELP4 rs986527 polymorphism affected the incidence of clinical symptoms and the levels of TNF-α and IL-1β in patients with intracranial arachnoid cysts.

RNF213 p.R4810K Polymorphism and the Risk of Moyamoya Disease, Intracranial Major Artery Stenosis/Occlusion, and Quasi-Moyamoya Disease: A Meta-Analysis

BACKGROUND

Accumulating studies have reported that there is an association between the Ring finger protein 213 (RNF213) p.R4810K (rs112735431, c.14576G>A) single nucleotide polymorphism and the predisposition of moyamoya disease (MMD), intracranial major artery stenosis/occlusion (ICASO), quasi-moyamoya disease (quasi-MMD), and other vascular diseases. However, to this day, analyses about this association have remained scarce in the literature. We attempted to conduct a meta-analysis to systematically summarize and clarify the issue.

METHODS

Electronic databases dated up to January 2018 were searched, retrieved, and used. Revman 5.2 software and STATA version 12.0 were used for statistical analysis. The association between RNF213 p.R4810K and MMD, ICASO, and quasi-MMD were assessed by odds ratios and 95% confidence intervals using fixed effects models. Between-study heterogeneity was evaluated by I-squared (I2) statistics and sensitivity analysis was performed by omitting 1 study at a time. A funnel plot and Begg's test were used to assess the potential publication bias.

RESULTS

The outcomes showed a statistically significant association between RNF213 p.R4810K and MMD, ICASO, and quasi-MMD, especially in the dominant model. Apart from the first 2 diseases, no significant association was identified under the recessive, the homozygote, and the heterozygote models in ICASO.

CONCLUSIONS

RNF213 p.R4810K was associated with MMD, ICASO, and quasi-MMD in different genetic models. Subgroup analysis indicated highly significantly higher risk in the Japanese patients. However, further well-designed studies with larger sample size and comprehensive data are needed to confirm our findings and provide a profound conclusion.

Internal carotid artery stenosis: A novel surgical model for moyamoya syndrome

Moyamoya is a cerebrovascular disorder characterized by progressive stenosis of the intracranial internal carotid arteries. There are two forms: Disease and Syndrome, with each characterized by the sub-population it affects. Moyamoya syndrome (MMS) is more prominent in adults in their 20's-40's, and is often associated with autoimmune diseases. Currently, there are no surgical models for inducing moyamoya syndrome, so our aim was to develop a new animal model to study this relatively unknown cerebrovascular disease. Here, we demonstrate a new surgical technique termed internal carotid artery stenosis (ICAS), to mimic MMS using micro-coils on the proximal ICA. We tested for Moyamoya-like vasculopathies by fluorescently labelling the mouse cerebrovasculature with Di I for visualization and analysis of vessel diameter at the distal ICA and anastomoses on the cortical surface. Results show a significant narrowing of the distal ICA and anterior cerebral artery (ACA) in the Circle of Willis, as observed in humans. There is also a significant decrease in the number of anastomoses between the middle cerebral artery (MCA) and the ACA in the watershed region of the cortex. While further characterization is needed, this ICAS model can be applied to transgenic mice displaying co-morbidities as observed within the Moyamoya syndrome population, allowing a better understanding of the disease and development of novel treatments.

Rare variants of RNF213 and moyamoya/non-moyamoya intracranial artery stenosis/occlusion disease risk: a meta-analysis and systematic review

Background

The p.R4810K and other rare variants of ring finger protein 213 gene (RNF213) were illustrated as susceptibility variants for moyamoya (MMD) and non-moyamoya intracranial artery stenosis/occlusion disease (ICASO) recently. However, the effect sizes of p.R4810K were in great discrepancy even in studies of the same ethnic population and firm conclusions of other rare variants have been elusive given the small sample sizes and lack of replication. Thus, we performed this study to quantitatively evaluate whether or to what extent the rare variants of RNF213 contribute to MMD and ICASO in different populations.

Methods

A systematic search of PubMed, EMBASE, ISI web of science, CNKI, and WANFANG DATA was conducted up to 5 September 2017. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random- or fixed-effect models based on the between-study heterogeneity. The subgroup analyses were performed by the ethnicity and family history. Sensitivity and publication bias analysis were performed to test the robustness of associations. All the statistical analyses were conduct using STATA 12.0.

Results

Twenty studies including 2353 MMD cases and 5488 controls and 11 studies including 1778 ICASO cases and 3140 controls were included in this study. Pooled ORs indicated that RNF213 p.R4810K significantly increased MMD and ICASO risk in East Asians with great effect sizes of discrepancy (dominant model: odds ratios 184.04, 109.77, and 31.53 and 10.07, 28.52, and 5.59 for MMD and ICASO, respectively, in Japan, Korea, and China). It significantly increased familial MMD risk in Japan, Korea, and China with 5 ~ 36 times larger effect sizes than that for sporadic ones in each country (dominant model ORs 1802.44, 512.42, 1109.02 and 134.35, 99.82, and 30.52, respectively, for familial and sporadic cases). The effect sizes of RNF213 p.R4810K to sporadic MMD were 3 ~ 4 times larger in Japan and Korea than those in China. RNF213 p.R4810K also increased the ICASO risk in Japan and Korea with 2 ~ 4 times larger effect sizes than that in China (dominant model ORs 10.71, 28.52, and 5.59, respectively). Another two rare variants- p.E4950D and p.A5021V significantly increased MMD risk in Chinese population (dominant model ORs 9.06 and 5.01, respectively). Various other rare variants in RNF213 were identified in Japanese, Chinese, European, and Hispanic American populations without association evidence available yet.

Conclusions

This meta-analysis shows the critical roles of RNF213 p.R4810K in MMD especially familial MMD and ICASO in Japan, Korea, and China. Except for RNF213 p.R4810K, MMD seems to have more complex determiners in China. Distinct genetic background exists and other environmental or genetic factor(s) may contribute to MMD. Studies focused on delineating the ethnicity-specific factors and pathological role of RNF213 variants in MMD and ICASO are needed.

Electronic supplementary material

The online version of this article (10.1186/s12199-017-0680-1) contains supplementary material, which is available to authorized users.