FPGT encodes GDP-L-fucose pyrophosphorylase, an enzyme that catalyzes the formation of GDP-L-fucose from GTP and L-fucose-1-phosphate 1. The enzyme functions as a salvage pathway to reutilize L-fucose arising from the turnover of glycoproteins and glycolipids 1, with highest expression in kidney tissue 1. Substrate specificity is primarily determined by the purine base of the nucleotide, followed by the nature of the hexose-1-phosphate and ribose moiety 2. FPGT participates in fucose metabolism alongside de novo synthesis pathways controlled by other enzymes; coordinated upregulation of these fucosylation genes occurs during inflammation and tumorigenesis 3. In hepatocellular carcinoma, the de novo synthesis genes GMDS and TSTA3 show amplification more frequently than salvage pathway genes 4. Genome-wide association studies have identified variants in the FPGT-TNNI3K/TNNI3K locus as associated with estimated glomerular filtration rate in patients with sickle cell disease 567. FPGT variants have also been tentatively associated with chr1 pain and major depressive disorder 8. These genetic associations suggest FPGT may influence renal function and neuropsychiatric phenotypes, though functional mechanisms remain to be established.