Primary hyperoxaluria is a rare disorder of glycoxylate metabolism characterized by an excess of oxalate resulting in manifestations ranging from occasional renal stones, recurrent nephrolithiasis and nephrocalcinosis to end-stage renal disease and systemic oxalosis. Presenting symtoms may commence from the neonatal period to adulthood. Three different types are well recognized: primary hyperoxaluria type 1, type 2 and type 3 (see these terms).