DNA analysis for patients with PH-1 is of pivotal interest, since (1) a small number of patients with the Gly170Arg AGXT mutation (Western Europe) may present with evidence of pyridoxine responsiveness, sometimes allowing isolated kidney Tx with lifelong pyridoxine intake and (2) patients with the Ile244Thr AGXT mutation (North Africa, Spain) do not respond to pyridoxine and, therefore, require combined liver and kidney Tx; (3) experience of other mutations is limited and leads to the recommendation of combined liver and kidney Tx [45–47]. This evidence concerns the gene AGXT and primary hyperoxaluria type 1.