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.