Primary hyperoxaluria is a group of inherited diseases with autosomal recessive inheritance (ARD), resulting from an inborn disorder of hepatic glyoxylate metabolism responsible for excessive oxalate production and increased urinary oxalate excretion.This disorder leads to precipitation of highly insoluble oxalate in the form of calcium oxalate crystals in the kidneys, resulting in nephrocalcinosis, recurrent urinary lithiasis (LU) and frequent progression to chronic renal failure (CKD). When renal function is impaired, elevated oxalemia leads to systemic oxalosis, corresponding to calcium oxalate deposition in various tissues, mainly bone, but also the cardiovascular system, skin, retina, etc.