Phosphoglycerate mutase (PGAM) catalyzes the reversible reaction of 3-phosphoglycerate (3-PGA) to 2-phosphoglycerate (2-PGA) in the glycolytic pathway. 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). PGAM2 encodes muscle-specific PGAM subunit. Mutations in this gene cause muscle phosphoglycerate mutase eficiency, also known as glycogen storage disease X.Synonyms: BPG-dependent PGAM 2, Muscle-specific phosphoglycerate mutase, PGAM 2, PGAM-M, PGAMM, Phosphoglycerate mutase 2, Phosphoglycerate mutase isozyme M