Hypoxanthine phosphoribosyltransferase 1 (HPRT1)

The HPRT1 gene provides instructions for producing an enzyme called hypoxanthine phosphoribosyltransferase 1. This enzyme allows cells to recycle purines, a type of building block of DNA and its chemical cousin RNA. Manufacturing purines uses more energy and takes more time than recycling purines, which makes recycling these molecules more efficient. Recycling purines ensures that cells have a plentiful supply of building blocks for the production of DNA and RNA. The process of recycling purines is also known as the purine salvage pathway.

What is the official name of the HPRT1 gene?

The official name of this gene is “hypoxanthine phosphoribosyltransferase 1.”

HPRT1 is the gene's official symbol. The HPRT1 gene is also known by other names, listed below.

How are changes in the HPRT1 gene related to health conditions?

Lesch-Nyhan syndrome - caused by mutations in the HPRT1 gene

More than 200 mutations in the HPRT1 gene have been found to cause Lesch-Nyhan syndrome. These mutations include changes in single DNA building blocks (nucleotides) or insertions or deletions of small amounts of DNA within the gene. These changes result in either nonfunctional or very low-function hypoxanthine phosphoribosyltransferase 1. Under these conditions, uric acid, a waste product of purine breakdown, accumulates in the body and can cause gouty arthritis (arthritis caused by uric acid in the joints), kidney stones, and bladder stones. It is unclear how this enzyme deficiency causes the neurological and behavioral problems characteristic of Lesch-Nyhan syndrome.

other disorders - caused by mutations in the HPRT1 gene

Certain mutations in the HPRT1 gene can also cause a condition featuring gouty arthritis called HPRT-related gout, previously known as Kelley-Seegmiller syndrome. Individuals with this condition have lower than normal levels of hypoxanthine phosphoribosyltransferase 1. Kidney problems commonly occur in people with this condition because a buildup of uric acid crystals can form kidney stones. Rarely, this condition will cause problems with the nervous system.

Where is the HPRT1 gene located?

Cytogenetic Location: Xq26.1

Molecular Location on the X chromosome: base pairs 133,421,922 to 133,462,361

The HPRT1 gene is located on the long (q) arm of the X chromosome at position 26.1.

More precisely, the HPRT1 gene is located from base pair 133,421,922 to base pair 133,462,361 on the X chromosome.

What other names do people use for the HPRT1 gene or gene products?

• Guanine Phosphoribosyltransferase
• HGPRT
• HGPRTase
• HOX5.4
• HPRT
• HPRTase
• HPRT_HUMAN
• Hypoxanthine-Guanine Phosphoribosyltransferase
• hypoxanthine phosphoribosyltransferase 1 (Lesch-Nyhan syndrome)
• IMP Pyrophosphorylase

External Links

Where can I find additional information about HPRT1?

You and your healthcare professional may find the following resources about HPRT1 helpful.

• Educational resources - Information pages (2 links)
• Gene Reviews - Clinical summary
• Gene Tests - DNA tests ordered by healthcare professionals

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

• PubMed - Recent literature
• OMIM - Genetic disorder catalog (2 links)
• Research Resources - Tools for researchers (4 links)

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

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

• What is DNA?
• What is a gene?
• How do genes direct the production of proteins?
• How can gene mutations affect health and development?

These links provide additional genetics resources that may be useful.

• Genetics education
• Human Genome Project
• Resources for Genetic Researchers

What glossary definitions help with understanding HPRT1?

acids ; arthritis ; cell ; deficiency ; deletion ; DNA ; enzyme ; gene ; gout ; guanine ; insertion ; joint ; kidney ; kidney stones ; molecule ; mutation ; nervous system ; neurological ; nucleotide ; purines ; RNA ; stone ; syndrome ; uric acid

References

• Duan J, Nilsson L, Lambert B. Structural and functional analysis of mutations at the human hypoxanthine phosphoribosyl transferase (HPRT1) locus. Hum Mutat. 2004 Jun;23(6):599-611. PubMed citation
• Entrez Gene
• Jinnah HA, De Gregorio L, Harris JC, Nyhan WL, O'Neill JP. The spectrum of inherited mutations causing HPRT deficiency: 75 new cases and a review of 196 previously reported cases. Mutat Res. 2000 Oct;463(3):309-26. Review. PubMed citation
• Nyhan WL. Dopamine function in Lesch-Nyhan disease. Environ Health Perspect. 2000 Jun;108 Suppl 3:409-11. Review. PubMed citation
• Nyhan WL. The recognition of Lesch-Nyhan syndrome as an inborn error of purine metabolism. J Inherit Metab Dis. 1997 Jun;20(2):171-8. Review. PubMed citation
• Puig JG, Torres RJ, Mateos FA, Ramos TH, Arcas JM, Buno AS, O'Neill P. The spectrum of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency. Clinical experience based on 22 patients from 18 Spanish families. Medicine (Baltimore). 2001 Mar;80(2):102-12. PubMed citation
• Sculley DG, Dawson PA, Emmerson BT, Gordon RB. A review of the molecular basis of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency. Hum Genet. 1992 Nov;90(3):195-207. Review. PubMed citation