Family-Based Moyamoya Susceptibility and Early Detection

This single-center, prospective, family-based observational cohort study aims to investigate susceptibility to moyamoya disease (MMD) and to develop strategies for early screening in individuals at increased familial risk. The study will enroll three groups: patients with MMD, their first-degree relatives, and healthy controls without a family history of MMD. The rationale for this study is that MMD has an important genetic component, but genetic susceptibility alone does not fully explain disease onset. Current diagnosis often relies on angiographic evaluation after symptoms have already appeared. This study seeks to identify earlier, less invasive biological and imaging markers that may help detect individuals at high risk before overt clinical disease develops. At baseline, participants will undergo collection of demographic and clinical data, vascular risk factors, neurological assessments, routine laboratory testing, and 5T high-resolution magnetic resonance imaging. Biospecimens including blood, urine, stool, saliva, and nasal swabs will be collected for multi-omics and biomarker analyses; surgically obtained tissue specimens may also be collected from patients undergoing clinically indicated surgery. Participants in the patient and first-degree relative groups will be followed annually for 3 years, primarily by telephone or online questionnaire, with optional repeat 5T MRI during follow-up. The primary objective is to identify baseline biological and imaging features associated with incident MMD in first-degree relatives and to establish an interpretable early-screening framework for high-risk populations.