GSN and metachromatic leukodystrophy: In PB, GSN mRNA levels were also significantly low in MDS including single-lineage dysplasia (1 case) or multi-lineage dysplasia (MDS-MLD; 7 cases), and MDS with excess blasts-1 (MDS-EB-1 that is defined by increased myeloblasts of 5–9% in BM; 3 cases), compared to that in healthy (Figure 4C).