Phosphoglycerate mutase (PGAM) catalyzes the reversible reaction of 3-phosphoglycerate (3-PGA) to 2-phosphoglycerate (2-PGA) in the glycolytic pathway. Since both 3-PGA and 2-PGA are allosteric regulators of the pentose phosphate pathway (PPP) and glycine and serine synthesis pathways, respectively, PGAM2 may contribute to the biosynthesis of amino acids, 5-carbon sugar, and nucleotides precursors. The PGAM is a dimeric enzyme containing, in different tissues, different proportions of a slow-migrating muscle (MM) isozyme, a fast-migrating brain (BB) isozyme, and a hybrid form (MB). Mutations in this gene cause muscle phosphoglycerate mutase deficiency, also known as glycogen storage disease X. PGAM2 is one of two PGAM subunits found in humans and is predominantly expressed in adult muscle.