Abstract T P165: Prospective Screening of Family Members With Moyamoya Disease Patients

Abstract

Background: Genetic factor plays an important role in the pathogenesis of moyamoya disease (MMD). Previous studies concentrated on the familial patients. In this study, we focus on the family members of sporadic MMD patients, and aim to gain a clearer understanding of the role that genetic factor plays in MMD. Methods: The immediate family members of MMD patients were initially screened by Transcranial Doppler Sonography (TCD) and the positive cases were verified by Magnetic Resonance Angiography (MRA). A total of 285 immediate family members of 245 sporadic MMD patients (2011.07-2013.03) were screened. Results: 33 cases were confirmed positive at 11.6% detection rate. 21 cases (from 20 index MMD patients) was validated by MRA. As a result, the proportion of familial MMD patients in our hospital increased from 7% (38/527) to 15% (79/527) in this period. For the main segments of the circle of Willis, which include the anterior cerebral arteries (ACA), middle cerebral arteries (MCA) and posterior cerebral arteries (PCA), the accordant rate between TCD and MRA was 95% (91/96). Kappa values for ACA, MCA and PCA were 0.91, 0.72 and 0.47 respectively. The familial cases confirmed by our screening showed a significant higher percentage of asymptomatic patients (57%) comparing to the 9% from the 38 familial MMD patients who had a clear family history before. Conclusions: Familial MMD patients may account for a higher percentage among all cases than previously thought. Some of the family member of MMD patients may also have MMD but present with asymptomatic. A routine screening should be implemented for all family members of MMD patients to improve the detection rate for this part of patient base. TCD has a high diagnostic agreement with MRA for MMD. By contrast, TCD may be a preferred choice for screening, because it’s inexpensive and safe.