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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 2012

What is the official name of the APRT gene?

The official name of this gene is “adenine phosphoribosyltransferase.”

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

What is the normal function of the APRT gene?

The APRT gene provides instructions for making an enzyme called adenine phosphoribosyltransferase (APRT). This enzyme is produced in all cells and is part of the purine salvage pathway, which recycles a group of DNA building blocks (nucleotides) called purines to make other molecules. The APRT enzyme helps to recycle the purine adenine to make a molecule called adenosine monophosphate (AMP). This conversion occurs when AMP is needed as a source of energy for cells.

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

adenine phosphoribosyltransferase deficiency - caused by mutations in the APRT gene

At least 40 mutations in the APRT gene have been found to cause adenine phosphoribosyltransferase (APRT) deficiency, a condition that affects the kidneys and urinary tract. Most of these mutations change single protein building blocks (amino acids) in the APRT enzyme. The mutations that cause APRT deficiency are categorized into two groups known as the APRT*J allele and the APRT*Q0 allele. The APRT*J allele consists of one mutation that replaces the amino acid methionine with the amino acid threonine at position 136 in the APRT enzyme (written as Met136Thr or M136T). This mutation reduces the function of the enzyme. The M136T mutation occurs almost exclusively in Japanese individuals with the condition; most affected individuals have this mutation on both copies of the APRT gene in each cell. The APRT*Q0 allele consists of all other APRT gene mutations. The most common of these mutations (written IVS4+2insT) alters the genetic instructions used to make the enzyme, resulting in an abnormally short, nonfunctional enzyme. This mutation is estimated to occur in 40 percent of affected Europeans.

APRT gene mutations lead to a lack of functional enzyme that prevents the conversion of adenine to AMP. As a result, adenine is converted to another molecule called 2,8-dihydroxyadenine (2,8-DHA). 2,8-DHA crystallizes in urine, forming stones in the kidneys and urinary tract. As a result, kidney function can decline, which may lead to end-stage renal disease (ESRD), a life-threatening failure of kidney function.

Where is the APRT gene located?

Cytogenetic Location: 16q24

Molecular Location on chromosome 16: base pairs 88,809,469 to 88,811,934

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

The APRT gene is located on the long (q) arm of chromosome 16 at position 24.

The APRT gene is located on the long (q) arm of chromosome 16 at position 24.

More precisely, the APRT gene is located from base pair 88,809,469 to base pair 88,811,934 on chromosome 16.

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

Where can I find additional information about APRT?

You and your healthcare professional may find the following resources about APRT 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 APRT gene or gene products?

  • AMP diphosphorylase
  • AMP pyrophosphorylase
  • APRTase

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

What glossary definitions help with understanding APRT?

acids ; adenine ; allele ; amino acid ; cell ; deficiency ; DNA ; end-stage renal disease ; enzyme ; ESRD ; gene ; kidney ; methionine ; molecule ; mutation ; protein ; purines ; renal ; renal disease ; stage ; threonine

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


  • Bollée G, Dollinger C, Boutaud L, Guillemot D, Bensman A, Harambat J, Deteix P, Daudon M, Knebelmann B, Ceballos-Picot I. Phenotype and genotype characterization of adenine phosphoribosyltransferase deficiency. J Am Soc Nephrol. 2010 Apr;21(4):679-88. doi: 10.1681/ASN.2009080808. Epub 2010 Feb 11. (
  • Bollée G, Harambat J, Bensman A, Knebelmann B, Daudon M, Ceballos-Picot I. Adenine phosphoribosyltransferase deficiency. Clin J Am Soc Nephrol. 2012 Sep;7(9):1521-7. Epub 2012 Jun 14. Review. (
  • NCBI Gene (
  • Silva M, Silva CH, Iulek J, Thiemann OH. Three-dimensional structure of human adenine phosphoribosyltransferase and its relation to DHA-urolithiasis. Biochemistry. 2004 Jun 22;43(24):7663-71. (


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 2012
Published: February 8, 2016