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Moyamoya disease is an idiopathic vascular disorder of intracranial arteries. Its susceptibility locus has been mapped to 17q25.3 in Japanese families, but the susceptibility gene is unknown. Genome-wide linkage analysis in eight three-generation families with moyamoya disease revealed linkage to 17q25.3 (P<10(-4)). Fine mapping demonstrated a 1.5-Mb disease locus bounded by D17S1806 and rs2280147. We conducted exome analysis of the eight index cases in these families, with results filtered through Ng criteria. There was a variant of p.N321S in PCMTD1 and p.R4810K in RNF213 in the 1.5-Mb locus of the eight index cases. The p.N321S variant in PCMTD1 could not be confirmed by the Sanger method. Sequencing RNF213 in 42 index cases confirmed p.R4810K and revealed it to be the only unregistered variant. Genotyping 39 SNPs around RNF213 revealed a founder haplotype transmitted in 42 families. Sequencing the 260-kb region covering the founder haplotype in one index case did not show any coding variants except p.R4810K. A case-control study demonstrated strong association of p.R4810K with moyamoya disease in East Asian populations (251 cases and 707 controls) with an odds ratio of 111.8 (P = 10(-119)). Sequencing of RNF213 in East Asian cases revealed additional novel variants: p.D4863N, p.E4950D, p.A5021V, p.D5160E, and p.E5176G. Among Caucasian cases, variants p.N3962D, p.D4013N, p.R4062Q and p.P4608S were identified. RNF213 encodes a 591-kDa cytosolic protein that possesses two functional domains: a Walker motif and a RING finger domain. These exhibit ATPase and ubiquitin ligase activities. Although the mutant alleles (p.R4810K or p.D4013N in the RING domain) did not affect transcription levels or ubiquitination activity, knockdown of RNF213 in zebrafish caused irregular wall formation in trunk arteries and abnormal sprouting vessels. We provide evidence suggesting, for the first time, the involvement of RNF213 in genetic susceptibility to moyamoya disease.

Moyamoya disease is a cerebrovascular condition predisposing affected patients to stroke in association with progressive stenosis of the intracranial internal carotid arteries and their proximal branches. Patients with characteristic moyamoya vasculopathy plus associated conditions are categorized as having moyamoya syndrome. This review describes the demographic characteristics, pathogenesis, evaluation, and treatment of moyamoya disease and syndrome. Moyamoya Moyamoya disease is a cerebrovascular condition predisposing affected patients to stroke in association with progressive stenosis of the intracranial internal carotid arteries and their proximal branches. This review describes the demographic characteristics, pathogenesis, evaluation, and treatment of moyamoya disease and syndrome. The moyamoya syndrome is a cerebrovascular condition that predisposes affected patients to stroke in association with progressive stenosis of the intracranial internal carotid arteries and their proximal branches. Reduced blood flow in the major vessels of the anterior circulation of the brain leads to compensatory development of collateral vasculature by small vessels near the apex of the carotid, on the cortical surface, leptomeninges, and branches of the external carotid artery supplying the dura and the base of the skull. In rare cases, this process also involves the posterior circulation, including the basilar and posterior cerebral arteries. First described in 1957 . . .

RNF213 is the major susceptibility factor for Moyamoya disease, a progressive cerebrovascular disorder that often leads to brain stroke in adults and children. Characterization of disease-associated mutations has been complicated by the enormous size of RNF213. Here, we present the cryo-EM structure of mouse RNF213. The structure reveals the intricate fold of the 584 kDa protein, comprising an N-terminal stalk, a dynein-like core with six ATPase units, and a multidomain E3 module. Collaboration with UbcH7, a cysteine-reactive E2, points to an unexplored ubiquitin-transfer mechanism that proceeds in a RING-independent manner. Moreover, we show that pathologic MMD mutations cluster in the composite E3 domain, likely interfering with substrate ubiquitination. In conclusion, the structure of RNF213 uncovers a distinct type of an E3 enzyme, highlighting the growing mechanistic diversity in ubiquitination cascades. Our results also provide the molecular framework for investigating the emerging role of RNF213 in lipid metabolism, hypoxia, and angiogenesis. Moyamoya disease is a genetic disorder affecting both adults and children. It is characterized by narrowing of the blood vessels in the brain, which can lead to strokes. Moyamoya patients often have mutations in the gene for a protein called RNF213. This protein is linked to multiple processes in the body, including the development of blood vessels. Despite this, its role in Moyamoya disease is still something of a mystery. RNF213 is known to fall into two protein ‘classes’. First, it is an E3 enzyme. This type of protein tags unwanted or defective proteins for disposal by the cell. Second, it is a motor protein. Motor proteins contain tiny molecular ‘engines’, called ATPases, that normally convert chemical energy to movement. No other human protein combines these two activities, making RNF213 unique. RNF213 is also an extremely large protein, which means it is difficult to manipulate in the laboratory and thus hard to study. Scientists still need more detailed information on RNF213’s structure and chemical activity before we can understand what the mutant protein might be doing in Moyamoya disease. Ahel et al. therefore set out to make the RNF213 protein and ‘dissect’ it in a test tube. Electron microscopy experiments using the mouse-version of RNF213 revealed that it consisted of a single, giant molecule, folded up to form three regions with distinct structures. These were a long ‘arm’ at one end, a ring-shaped part in the middle, containing the ATPase ‘motor’, and the E3 enzyme module at the other end. Further chemical analysis showed that RNF213’s ATPase and E3 modules worked in unexpected ways. Although the ATPase did resemble another well-known motor protein, in RNF213 it did not generate movement but rather appeared to act like an intricate molecular ‘switch’. The E3 module of RNF213 ‘tagged’ other molecules as expected but did not contain an additional structure that all other known E3 enzymes need to work properly. This suggests that RNF213 represents a distinct class of E3 enzymes. Biochemical tests of the mutation most commonly found in Moyamoya patients revealed that it left RNF213’s overall structure, ATPase motor and E3 module intact. That is, the disease-causing mutation appeared to hinder interactions with other partner proteins, rather than disrupting RNF213 itself. By providing the first detailed molecular description of the architecture of RNF213, Ahel et al. hope that these findings will help future investigations of both this giant protein’s biological role in the cell and its contribution to Moyamoya disease.

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive spontaneous bilateral occlusion of the intracranial internal cerebral arteries (ICA) and their major branches with compensatory capillary collaterals resembling a “puff of smoke” (Japanese: Moyamoya) on cerebral angiography. These pathological alterations of the vessels are called Moyamoya arteriopathy or vasculopathy and a further distinction is made between primary and secondary MMD. Clinical presentation depends on age and population, with hemorrhage and ischemic infarcts in particular leading to severe neurological dysfunction or even death. Although the diagnostic suspicion can be posed by MRA or CTA, cerebral angiography is mandatory for diagnostic confirmation. Since no therapy to limit the stenotic lesions or the development of a collateral network is available, the only treatment established so far is surgical revascularization. The pathophysiology still remains unknown. Due to the early age of onset, familial cases and the variable incidence rate between different ethnic groups, the focus was put on genetic aspects early on. Several genetic risk loci as well as individual risk genes have been reported; however, few of them could be replicated in independent series. Linkage studies revealed linkage to the 17q25 locus. Multiple studies on the association of SNPs and MMD have been conducted, mainly focussing on the endothelium, smooth muscle cells, cytokines and growth factors. A variant of the RNF213 gene was shown to be strongly associated with MMD with a founder effect in the East Asian population. Although it is unknown how mutations in the RNF213 gene, encoding for a ubiquitously expressed 591 kDa cytosolic protein, lead to clinical features of MMD, RNF213 has been confirmed as a susceptibility gene in several studies with a gene dosage-dependent clinical phenotype, allowing preventive screening and possibly the  development of new therapeutic approaches. This review focuses on the genetic basis of primary MMD only.

East Asia has one of the highest global stroke burdens. Genetically, moyamoya disease (MMD) and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) contribute to this burden. This study investigated the allele frequencies and estimated the genetic prevalence of RNF213 and NOTCH3 variants in a large Korean population. Between July 2021 and August 2024, 129,933 individuals who underwent health checkups were included. RNF213 p.Arg4810Lys and three NOTCH3 variants, p.Arg544Cys, p.Arg640Cys, and p.Arg75Pro, were analyzed using next-generation sequencing. Allele frequencies were calculated, and genetic prevalence was estimated using the Hardy-Weinberg equilibrium. The allele frequency of RNF213 p.Arg4810Lys was 1.08%, with 13 homozygotes. The estimated genetic prevalence of MMD was 1 in 47 individuals. For NOTCH3, the allele frequencies were 0.07% for p.Arg544Cys, 0.07% for p.Arg640Cys, and 0.04% for p.Arg75Pro, corresponding to an estimated genetic prevalence of CADASIL of 1 in 277 individuals. Eight individuals carried both the RNF213 and NOTCH3 variants. This large-scale study highlights the substantial genetic burden of RNF213 and NOTCH3 variants in Koreans, which partially contributes to the high stroke burden in East Asia. These findings emphasize the importance of population-specific genetic studies to optimize cerebrovascular disorder management in East Asia.

Moyamoya disease (MMD) is a rare yet clinically significant cerebrovascular disorder characterized by progressive stenosis of the distal internal carotid artery and/or its principal branches, accompanied by the development of characteristic collateral vessel networks. This disease demonstrates a complex multifactorial etiology with strong genetic determinants, as evidenced by its distinct geographical distribution patterns and familial clustering. Recent genetic researches have identified multiple pathogenic mutations contributing to MMD development through three principal mechanisms: progressive vascular stenosis, abnormal angiogenesis, and dysregulated inflammatory responses. Furthermore, moyamoya syndrome frequently occurs as a secondary vascular complication in various monogenic disorders. This review provides a comprehensive analysis of recent genetic advances in MMD in view of diverse pathogenic pathways, offering valuable perspectives on the molecular mechanisms underlying disease development and potential therapeutic targets.

Moyamoya disease (MMD) is a chronic cerebrovascular disorder and a leading cause of pediatric stroke. Extracellular vesicles (EVs) carrying microRNAs (miRNAs) play a pivotal role in intercellular communication within cerebrovascular diseases. This study aimed to identify specific miRNAs within plasma-derived EVs from MMD patients and investigate their functional implications. Study subjects included healthy controls ( N  = 13) and MMD patients ( N  = 23). EVs were isolated from plasma samples and characterized by transmission electron microscopy, nanoparticle tracking analysis, ExoView, RT-qPCR, and immunoblotting. miRNA profiles were assessed through NanoString analysis. Functional effects of miR-512-3p inhibition were evaluated in MMD endothelial colony-forming cells (ECFCs) by analyzing guanosine triphosphatase (GTPase) activity, tubule formation, and cell viability. MMD-derived EVs exhibited an upregulation of miR-512-3p compared to controls. Bioinformatics analysis identified RHO guanine nucleotide exchange factor 3 (ARHGEF3) as a potential target of miR-512-3p. Inhibition of miR-512-3p in MMD ECFCs resulted in increased expression of ARHGEF3 and its downstream effector RHOA, leading to enhanced GTPase activity and improved tubule formation, indicative of restored angiogenic function. Elevated levels of miR-512-3p within plasma-derived EVs may serve as a novel biomarker for MMD diagnosis. The modulation of ARHGEF3 and subsequent RHOA signaling by targeting miR-512-3p contributes to the dysregulated angiogenesis in MMD.

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive stenosis of large intracranial arteries and a hazy network of basal collaterals called moyamoya vessels. A polymorphism (R4810K) in the Ring Finger Protein 213 ( RNF213 ) gene, at chromosome 17q25.3, is the strongest genetic susceptibility factor for MMD in East Asian populations. MMD was regarded prevalent in childhood and in East Asian populations. However, the so-called MMD could represent only the tip of the iceberg. MMD is increasingly reported in adult patients and in Western populations. Moreover, the RNF213 variant was recently reported to be associated with non-MMD disorders, such as intracranial atherosclerosis and systemic vasculopathy (e.g., peripheral pulmonary artery stenosis and renal artery stenosis). In this review, we summarize the spectrums of RNF213 vasculopathy in terms of clinical and genetic phenotypes. Continuous efforts are required for pathophysiology-based diagnoses and treatment, which will benefit from collaboration between clinicians and researchers, and between stroke and vascular physicians.

The ring finger protein 213 (RNF213) Arg4810Lys variant has been previously identified as a significant risk factor for Moyamoya disease (MMD), particularly in East Asian populations. This review explores the broader impact of the Arg4810Lys mutation on various cerebrovascular conditions, including Moyamoya syndrome (MMS), intracranial artery stenosis, quasi-Moyamoya syndromes, ischemic stroke, and intracranial atherosclerosis. Beyond the brain, it is also implicated in pulmonary arterial hypertension, coronary artery disease, and renal artery stenosis, emphasizing its systemic effects. Functional studies suggest that RNF213 Arg4810Lys alters angiogenic signaling, endothelial cell function, vascular remodeling, and immune response pathways, especially when influenced by environmental stressors, like hypoxia or inflammation. The gene dosage of Arg4810Lys significantly affects disease phenotypes, with homozygous carriers typically experiencing earlier onset with increased severe symptoms. The variant also exhibits incomplete penetrance and frequently co-occurs with additional genetic alterations, including trisomy, KIF1A, FLNA, and PCSK9 mutations, which complicates its pathogenicity. A comprehensive understanding of RNF213 Arg4810Lys’s systemic impact is essential to developing effective risk assessment strategies, personalized treatments, and targeted therapies for associated vascular diseases.

Moyamoya disease (MMD) is a rare cerebrovascular disorder characterized by progressive stenosis of large intracranial arteries and formation of fragile collateral vessels that can be triggered by a broad range of genetic and immune factors. Central to MMD pathology is excessive proliferation of vascular smooth muscle cells (VSMCs) in the intima of affected arteries associated with contractile-to-synthetic phenotypic switching, but the underlying molecular mechanisms remain unclear. To identify dysregulated pathways we studied a cohort of 12 patients with well-documented MMD, including one post-mortem autopsy case, using a multi-omics approach combining whole exome sequencing with plasma proteomics. In addition, we conducted an in-depth spatial proteomics analysis of an occluded artery retrieved post-mortem from one idiopathic patient, combining targeted antibody-based imaging with laser capture microdissection coupled to mass spectrometry. Genetic predispositions for MMD was found in 8 out of 12 patients (67%), including three patients with variants in the major susceptibility gene RNF213 and five with varying underlying genetic conditions (trisomy 21, pathogenic variants in ACTA2 , SAMHD1 , NFIA ). Artery spatial proteomics revealed phenotypic switching of vascular smooth muscle cells associated with infiltration of these cells in the intima, including loss of contractile and gain of synthetic marker proteins. Most notably, increased expression of cellular fibronectin in the occluded lesion was associated with increased levels in patients’ plasma, providing a rationale for cellular fibronectin as potential tissue leakage biomarker for moyamoya disease. Finally, infiltration of macrophages and antigen-presenting cells in the intima pointed to a role for inflammatory signals in disease progression. Together, our data provide an unprecedented spatial view on protein changes in an occluded moyamoya artery, revealing intimal infiltration of synthetic vascular smooth muscle cells and antigen-presenting immune cells as key pathological findings, opening novel avenues for future diagnosis and research.