Novel variants and clinical symptoms in four new ALG3‐CDG patients, review of the literature, and identification of AAGRP‐ALG3 as a novel ALG3 variant with alanine and glycine‐rich N‐terminus

ALG3-CDG is one of the very rare types of congenital disorder of glycosylation (CDG) caused by variants in the ER-mannosyltransferase ALG3. Here, we summarize the clinical, biochemical, and genetic data of four new ALG3-CDG patients, who were identified by a type I pattern of serum transferrin and the accumulation of Man5 GlcNAc2 -PP-dolichol in LLO analysis. Additional clinical symptoms observed in our patients comprise sensorineural hearing...