Phosphoglucomutase 1 (PGM1) is encoded by the PGM1 gene; PGM1 deficiency is a recognized inherited metabolic disorder (CDG1T) that is linked to a variety of diseases and disorders, including liver disease, exercise intolerance, and dilated cardiomyopathy, reflecting the key role played by the enzyme in glucose metabolism [12–14]. Here, PGM1 is linked to inborn errors of metabolism.