MONDO_0009823 (primary hyperoxaluria type 1) is a rare disorder of glyoxylate metabolism characterized by the accumulation of oxalate due to a deficiency of the peroxisomal hepatic enzyme L-alanine: glyoxylate aminotransferase (AGT). Clinical presentation is variable, ranging from occasional symptomatic nephrolithiasis to nephrocalcinosis and end-stage renal disease with systemic involvement. Also known as: AGXT primary hyperoxaluria, PH1, glycolic aciduria, peroxisomal alanine-glyoxylate aminotransferase deficiency, primary hyperoxaluria caused by mutation in AGXT, primary hyperoxaluria type I.