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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed October 2006

What is the official name of the ARG1 gene?

The official name of this gene is “arginase 1.”

ARG1 is the gene's official symbol. The ARG1 gene is also known by other names, listed below.

What is the normal function of the ARG1 gene?

The ARG1 gene provides instructions for producing the enzyme arginase. This enzyme participates in the urea cycle, a series of reactions that occurs in liver cells. The urea cycle processes excess nitrogen, which is generated when proteins and their building blocks (amino acids) are used by the body. Through the urea cycle, excess nitrogen is made into a compound called urea that is excreted by the kidneys. Excreting the excess nitrogen prevents it from accumulating in the form of ammonia, which is toxic.

Arginase controls the last step of the urea cycle, a reaction in which nitrogen is removed from the amino acid arginine and processed into urea for excretion from the body. A compound called ornithine is also produced in this reaction; it is needed for the urea cycle to repeat.

How are changes in the ARG1 gene related to health conditions?

arginase deficiency - caused by mutations in the ARG1 gene

Approximately 12 mutations have been identified in the ARG1 gene. A mutated ARG1 gene may result in an arginase enzyme that is unstable, shorter than usual or the wrong shape, or may prevent the enzyme from being produced at all.

The shape of an enzyme affects its ability to control a chemical reaction. If the arginase enzyme is misshapen or missing, it cannot fulfill its role in the urea cycle. Excess nitrogen is not converted to urea for excretion, and ammonia and arginine accumulate in the body. Ammonia is toxic, especially to the nervous system, and the accumulation of ammonia and arginine are believed to cause the neurological problems and other signs and symptoms of arginase deficiency.

Where is the ARG1 gene located?

Cytogenetic Location: 6q23

Molecular Location on chromosome 6: base pairs 131,573,203 to 131,584,332

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The ARG1 gene is located on the long (q) arm of chromosome 6 at position 23.

The ARG1 gene is located on the long (q) arm of chromosome 6 at position 23.

More precisely, the ARG1 gene is located from base pair 131,573,203 to base pair 131,584,332 on chromosome 6.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about ARG1?

You and your healthcare professional may find the following resources about ARG1 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the ARG1 gene or gene products?

  • A-I
  • arginase, liver
  • arginase, type I

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding ARG1?

acids ; amino acid ; ammonia ; arginine ; compound ; deficiency ; enzyme ; excretion ; gene ; nervous system ; neurological ; toxic ; urea

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Iyer R, Jenkinson CP, Vockley JG, Kern RM, Grody WW, Cederbaum S. The human arginases and arginase deficiency. J Inherit Metab Dis. 1998;21 Suppl 1:86-100. Review. (
  • Iyer RK, Yoo PK, Kern RM, Rozengurt N, Tsoa R, O'Brien WE, Yu H, Grody WW, Cederbaum SD. Mouse model for human arginase deficiency. Mol Cell Biol. 2002 Jul;22(13):4491-8. (
  • NCBI Gene (
  • Vockley JG, Goodman BK, Tabor DE, Kern RM, Jenkinson CP, Grody WW, Cederbaum SD. Loss of function mutations in conserved regions of the human arginase I gene. Biochem Mol Med. 1996 Oct;59(1):44-51. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: October 2006
Published: February 1, 2016