(A) Phase contrast images of COG7-CDG patient fibroblasts reveled that ~30% of cells contain vacuoles (arrows). (B) EM analysis of patient fibroblasts indicates abundant vacuole-like EELS structures throughout the cell, though smaller than those in HEK293T cells (arrows). (C) Immunostaining of COG7-CDG patient fibroblasts and control fibroblasts reveal enlarged Lamp2 positive EELS in patient fibroblasts but not in control. (D and E) COG7-CDG patient fibroblasts and control fibroblasts lysates and concentrated conditioned media were analyzed for Cathepsin D (D), Col6A1, GPP130, and α-tubulin (E). Col6A1 and cathepsin D were secreted 3× more in COG7-CDG patient cells than control (n=2, calculated via densitometry) while transmembrane protein GPP130 was not secreted in either. α-tubulin was used as a control for lysis. Scale bars are 5μm.