Primary hyperoxalurias (PH) are very rare diseases characterised by overproduction and accumulation of oxalate in the body. The main target organ is the kidney, as oxalate cannot be metabolised and is excreted in the urine, leading to nephrocalcinosis, recurrent urolithiasis, and subsequent renal impairment. During the last decade, major advances in enzymology, molecular genetics, and cell biol...