Does the GCKR rs1260326 T allele increase triglycerides, fatty liver risk, and uric acid levels?

The GCKR rs1260326 T allele (specifically the Pro446Leu substitution) is a well-characterized genetic variant that acts as a pleiotropic regulator of systemic metabolism. While it is associated with lower fasting glucose and a reduced risk of type 2 diabetes, it simultaneously increases the risk for several metabolic conditions including hypertriglyceridemia, non-alcoholic fatty liver disease (NAFLD), and hyperuricemia.

Clinical and metabolic evidence

• Triglyceride levels: Large-scale genetic studies, including the DESIR cohort and Taiwan Biobank, demonstrate that each copy of the minor T allele is associated with a significant increase in serum triglycerides, estimated at approximately 3.41% per allele.
• Fatty liver risk: Evidence from a meta-analysis of 25 studies indicates that the T allele robustly increases the risk of NAFLD. The odds ratio (OR) is approximately 1.32 per risk allele, rising to 1.65 for individuals carrying the TT genotype compared to the CC genotype.
• Uric acid and gout: Genome-wide association studies (GWAS) identify this locus as a major driver of serum uric acid concentrations ($p = 1.9 \times 10^{-12}$). Carriers of the T allele have an increased risk of hyperuricemia (up to 2.29-fold in certain populations) and an OR of 1.36 for developing gout.

Mechanistic explanations

• The GKRP-GK Switch: The GCKR gene encodes the glucokinase regulatory protein (GKRP), which normally binds and inhibits glucokinase (GK) in the liver during fasting. The rs1260326 T allele weakens this inhibitory interaction, leading to constitutive (constant) GK activity in the cytoplasm.
• De novo lipogenesis: Increased GK activity drives hepatic glucose uptake and enhances glycolytic flux. This provides an abundance of substrates for de novo lipogenesis (DNL), leading to the overproduction of triglycerides and their accumulation in hepatocytes (steatosis).
• Purine metabolism: The metabolic shift also impacts the purine biosynthetic pathway. Enhanced flux through early glycolytic stages can shunt intermediates into the pentose phosphate pathway and modulate enzymes such as Nt5e and Ppat, ultimately increasing the production of uric acid.

Bottom line

The GCKR rs1260326 T allele is a validated risk factor for elevated triglycerides, NAFLD, and high uric acid levels. These effects are driven by a gain-of-function mechanism in hepatic glucose processing that prioritizes fat and purine synthesis over systemic glucose maintenance.