Phosphoglucomutase-1 deficiency, also referred to as PGM1-CDG (Congenital Disorder of Glycosylation type 1t), is a rare genetic disorder previously classified as Glycogen Storage Disease type 14 (GSD XIV). It is an autosomal recessive condition, meaning it requires mutations in both copies of the PGM1 gene for the disorder to manifest. The PGM1 gene encodes the phosphoglucomutase-1 enzyme, which plays a critical role in carbohydrate metabolism by catalyzing the interconversion of glucose-1-phosphate and glucose-6-phosphate. This process is essential for glycogen synthesis and breakdown, as well as for producing UDP-glucose and UDP-galactose, which are necessary for protein glycosylation.
The disorder affects multiple organ systems due to its impact on both glycogen metabolism and protein glycosylation, making it a mixed-type congenital disorder of glycosylation (CDG). Research indicates it is extremely rare, with limited prevalence data, but it is recognized as a multisystem disease with significant clinical variability.