GRHPR encodes an enzyme with hydroxypyruvate reductase, glyoxylate reductase, and D-glycerate dehydrogenase enzymatic activities. The enzyme has widespread tissue expression and has a role in metabolism. Type II hyperoxaluria is caused by mutations in this gene.

The GRHPR gene encodes a predicted 328-amino acid protein with a calculated molecular mass of 35.5 kD. By transient transfection of the cDNA clone into COS cells, Cramer et al. (1999) verified that GRHPR encodes an enzyme with hydroxypyruvate reductase, glyoxylate reductase, and D-glycerate dehydrogenase enzymatic activities. Database analysis of human ESTs revealed widespread tissue expression, indicating that the enzyme may have a role in metabolism.