Genes encoding myelin-specific proteins 2’,3’-cyclic nucleotide 3’-phosphodiesterase (CNP), oligodendrocyte myelin paranodal inner loop protein (OPALIN), myelin-associated glycoprotein (MAG), and myelin and lymphocyte (MAL) were significantly downregulated in preclinical fucosidosis-affected cortex [21], consistent with a 56 % loss of oligodendrocytes [4] and the decline in the density of LFB/PAS stained tracts. Here, OPALIN is linked to fucosidosis.