Role of the Variant in Vascular Outcomes in Patients With Intracranial Atherosclerosis.

Background The ( gene) variant R4810K is a susceptibility allele not only for Moyamoya disease (MMD) but also for intracranial atherosclerosis (ICAS) in East Asian populations. We hypothesized that this variant would affect the distribution of ICAS and recurrence of cerebrovascular events. Methods and Results We conducted a prospective study of patients with ICAS and MMD using high-resolution magnetic resonance imaging and R4810K genotyping. Patients were included in the ICAS group when relevant plaques existed on high-resolution magnetic resonance imagingand in the MMD group when they carried the variant and high-resolution magnetic resonance imaging showed no plaques but characteristic features of MMD. We compared clinical and neuroimaging features of patients with ICAS-+ with patients with ICAS-- and of patients with MMD. Of 477 patients, 238 patients were in the ICAS group and 239 were in the MMD group. Among patients with ICAS, 79 patients (33.2%) were in the ICAS-+ group and 159 (66.8%) in the ICAS-- group. Tandem lesions were significantly more common in the ICAS- group than in the ICAS-- group (40.3% versus 72.2%, <0.001), and their distributions were similar between the ICAS- and MMD groups. The presence of the R4810K variant (hazard ratio [HR], 3.203; 95% CI, 1.149-9.459; =0.026) and tandem lesions (≥3) (HR, 8.315; 95% CI, 1.930-39.607; =0.005) were independently associated with recurrent cerebrovascular events. Conclusions Patients with ICAS carrying the R4810K variant showed clinical and imaging features distinct from patients with ICAS without the variant, suggesting that the R4810K variant plays a role in intracranial atherosclerosis in East Asian patients.