There are many steps in glycosylation, each of which is controlled by a different gene. The type of CDG a person has depends on which gene is involved. The signs and symptoms of PGM1-CDG can be different from person to person. They may include cleft palate or bifid uvula; low blood sugar (hypoglycemia); endocrine disorders; muscle disease, leading to muscle weakness or death of muscle fibers (rhabdomyolysis); liver disease; blood clotting problems; and a weak and enlarged heart chamber (dilated cardiomyopathy). Some people with PGM1-CDG have central nervous system involvement such as seizures, development delay, or intellectual disability. PGM1-CDG is caused by genetic changes in the PGM1 gene and inheritance is autosomal recessive. The diagnosis may be suspected based on symptoms and specific blood test results, and it is confirmed with genetic testing. The course of the disorder and whether symptoms or complications may affect the lifespan are difficult to predict and vary among people with PGM1-CDG.