-Related Vasculopathy: An Entity with Diverse Phenotypic Expressions.

Moyamoya disease (MMD) is primarily associated with genetic variants in . p.R4810K (c.14429G>A, p.Arg4810Lys) is a founder variant predominantly found in East Asian populations and is strongly associated with MMD, a rare cerebrovascular condition characterized by progressive stenosis of intracranial arteries and the development of abnormal collateral networks. Recent evidence suggests that variants are also enriched in non-moyamoya intracranial arteriopathies, such as large-artery atherosclerotic stroke and intracranial arterial stenosis/occlusion (ICASO), particularly in east Asian individuals with early-onset or cryptogenic stroke. This expanded phenotypic spectrum, termed -related vasculopathy (RRV), represents a distinct pathogenic entity that may involve unique pathogenic processes separate from traditional atherosclerosis. In this review, we synthesize current genetic, clinical, radiological, and experimental findings that delineate the unique features of RRV. Patients with RRV typically exhibit a lower burden of traditional vascular risk factors, negative vascular remodeling in the absence of atheromatous plaques, and an increased propensity for disease progression. variants may compromise vascular resilience by impairing adaptive responses to hemodynamic stress. Furthermore, emerging cellular and animal model data indicate that influences angiogenesis, lipid metabolism, and stress responses, offering mechanistic insights into its role in maintaining vascular integrity. Recognizing RRV as a distinct clinical entity has important implications for diagnosis, risk stratification, and the development of genome-informed therapeutic strategies.