The third type of glucose 6-phosphatase deficiency, glucose 6-phosphatase-β deficiency, is characterized by a congenital neutropenia syndrome in which neutrophils exhibit enhanced endoplasmic reticulum (ER) stress, increased apoptosis, impaired energy homeostasis, and impaired functionality. It can also lead to cardiac and urogenital malformations. This third class of deficiency is also affected by a G6PT deficiency as glucose-6-phosphatase-β also lies within the ER lumen and thus can lead to similar symptoms of glucose-6-phosphatase-β deficiency be associated with GSD-1b. Furthermore, recent studies have elucidated this area of similarity between both deficiencies and have shown that aberrant glycosylation occurs in both deficiencies. The neutrophil glycosylation has a profound effect on neutrophil activity and thus may also be classified as a congenital glycosylation disorder as well.