COL2A1 and Leigh syndrome: Of the 17 pairs covering 13 unique proteins, 9 proteins were associated with 1 imaging feature of SVD; 3 proteins (APOE, PEAR1 [platelet endothelial aggregation receptor 1], and HEXIM1 [hexamethylene bis-acetamide-inducible protein 1]) were associated with ≥2 neuroimaging markers; 1 protein (COL2A1 [collagen type II α-1 chain]) was associated with LS (Figure 2A).