Congenital Disorders of Glycosylation (CDG) are a group of some 200 genetic disorders with PMM2-CDG being the most common disease. These disorders individually remain rare with poorly understood natural history (NH) and causes of mortality. We established a NH study for CDG and collected both prospective and retrospective data on CDG outcomes. In the current data set analysis on deceased patients, we describe the clinical phenotype and causes of death for thirty-seven individuals with various genetic causes of CDG.