CTSA and lysosomal storage disease: Cathepsin A‐related arteriopathy with strokes and leukoencephalopathy (CARASAL) is a cerebral small vessel disease associated with a recessive mutation in the gene encoding cathepsin A that causes galactosialidosis, a lysosomal storage disorder (Caciotti et al., 2013; van der Knaap & Bugiani, 2017).