ALG10 encodes an alpha-1,2-glucosyltransferase that catalyzes the final step in the biosynthesis of dolichol-linked oligosaccharides, essential precursors for N-linked protein glycosylation 1. The enzyme specifically adds the third glucose residue to produce Glc(3)Man(9)GlcNAc(2)-PP-Dol in the endoplasmic reticulum lumen 2. ALG10 plays a critical role in maintaining normal neurological function, as demonstrated by Drosophila models showing that Alg10 loss leads to altered neuronal firing, sleep disorders, seizures, and cardiovascular abnormalities 1. The gene has been associated with congenital disorders of glycosylation (CDG), with a human patient homozygous for variants in both ALG10 and ALG10B presenting with epilepsy, brain atrophy, and sleep abnormalities 1. In cancer research, ALG10 contributes to colorectal cancer stemness through a positive regulatory loop with TGF-β signaling, where ALG10 enhances TGFBR2 glycosylation while TGF-β promotes ALG10 expression 3. ALG10 also protects the cardiac HERG potassium channel from pharmacological block through its glucosyltransferase activity, potentially preventing drug-induced arrhythmias 2. Clinical significance includes associations with progressive myoclonus epilepsies, age-related hearing loss, and radiotherapy sensitivity in rectal cancer 456.