“…The pathogenic mechanisms underlying the acute and long-term organ-specific complications of classic galactosemia are complex and remain to be fully elucidated. Currently described contributing factors include accumulation of galactose metabolites (galactitol, galactonate and Gal-1-P) [ 2 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ], uridine diphosphate (UDP)-hexose alterations and impaired glycosylation [ 21 , 25 , 31 , 32 , 33 , 34 , 35 , 36 ], endoplasmic reticulum (ER) stress with subsequent unfolded protein response (UPR), induction and alteration of signaling pathways [ 2 , 3 , 4 , 37 , 38 , 39 , 40 , 41 , 42 ], and oxidative stress [ 4 , 29 , 43 , 44 ] ( Figure 1 ).…”