Arginase-1 is a cytosolic, manganese-dependent ureohydrolase that converts L-arginine and water to L-ornithine and urea. This homotrimeric enzyme contains a binuclear manganese cluster in each subunit and catalyzes the terminal step of the hepatic urea cycle, regenerating ornithine for nitrogen disposal. In human granulocytes it is stored in granules and can be released extracellularly, where arginine depletion suppresses T-cell proliferation and cytokine production. Granulocyte ARG1 also contributes to fungicidal activity; arginine depletion within the phagolysosome has been proposed as its antimicrobial mechanism. Loss-of-function variants cause arginase deficiency with hyperargininemia and progressive neurological disease.
Relationship is the entry's genetic[].relationship_type. untyped means the entry has a genetic record for the gene but does not type it; its free-text association is shown instead.
| Disorder | Relationship | Where the gene appears |
|---|---|---|
| Arginase Deficiency | untyped |
mechanism: ARG1 molecular function deficiency
|
| Urea Cycle Disorder | untyped |
mechanism: Arginine and guanidino compound neurotoxicity in ARG1 deficiency; Deficient urea cycle enzyme function
|
An entry matches when ClinGen's MONDO disease is the entry's own disease term, a subtype term, or an exact-match mapping. An amber status marks an entry ClinGen supports the gene for (Definitive, Strong or Moderate) whose own record does not type it. A Limited, Disputed or Refuted tier on such an entry is not a gap.
| ClinGen disease | MOI | Classification | dismech entry |
|---|---|---|---|
| arginase deficiency MONDO:0008814 | AR | Definitive 2020-06-29 |
Arginase Deficiency
untyped
|
Identity from HGNC (snapshot 2026-10-01). Page layers are described in the gene pages documentation.