Primary hyperoxaluria type I is an autosomal recessive disorder characterized by an accumulation of calcium oxalate in various bodily tissues, especially the kidney, resulting in renal failure. Affected individuals have decreased or absent AGXT activity and a failure to transaminate glyoxylate, which causes the accumulated glyoxylate to be oxidized to oxalate. This overproduction of oxalate results in the accumulation of nonsoluble calcium oxalate in various body tissues, with pathologic sequelae. Type III primary hyperoxaluria is caused by mutation in the mitochondrial dihydrodipicolinate synthase-like gene (DHDPSL) on chromosome 10q24. [From OMIM]