PGM1(Phosphoglucomutase-1) is also named as glucose phosphomutase 1 and belongs to the phosphohexose mutase family. It catalyzes the transfer of phosphate between the 1 and 6 positions of glucose. In most cell types,PGM1 isozymes predominate,representing about 90% of total PGM activity. One exception is red cells,where PGM2 is a major isozyme. Defects in PGM1 are the cause of glycogen storage disease type 14 (GSD14). It has 2 isoforms produced by alternative splicing.