Figure 3. Illustration of enzymatic defects in primary hyperoxaluria. A: Alanine glyoxylate aminotransferase (AGT1) defect seen in primary hyperoxaluria (PH) type 1. B: Glyoxylate/hydroxypyruvate reductase (GRHPR) defect seen in PH2. C: 4-hydroxy-2-oxoglutarate aldolase (HOGA) defect seen in PH3.