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Reviewed August 2014

What is the official name of the UPB1 gene?

The official name of this gene is “ureidopropionase, beta.”

UPB1 is the gene's official symbol. The UPB1 gene is also known by other names, listed below.

Read more about gene names and symbols on the About page.

What is the normal function of the UPB1 gene?

The UPB1 gene provides instructions for making an enzyme called beta-ureidopropionase. This enzyme is involved in the breakdown of molecules called pyrimidines, which are building blocks of DNA and its chemical cousin RNA.

The beta-ureidopropionase enzyme is involved in the last step of the process that breaks down pyrimidines. This step converts N-carbamyl-beta-aminoisobutyric acid to beta-aminoisobutyric acid and also breaks down N-carbamyl-beta-alanine to beta-alanine, ammonia, and carbon dioxide. Both beta-aminoisobutyric acid and beta-alanine are thought to play roles in the nervous system. Beta-aminoisobutyric acid increases the production of a protein called leptin, which has been found to help protect brain cells from damage caused by toxins, inflammation, and other factors. Research suggests that beta-alanine is involved in sending signals between nerve cells (synaptic transmission) and in controlling the level of a chemical messenger (neurotransmitter) called dopamine.

How are changes in the UPB1 gene related to health conditions?

beta-ureidopropionase deficiency - caused by mutations in the UPB1 gene

At least 16 UPB1 gene mutations have been identified in people with beta-ureidopropionase deficiency. This disorder causes excessive amounts of N-carbamyl-beta-aminoisobutyric acid and N-carbamyl-beta-alanine to be released in the urine. Affected individuals may also have a variety of neurological problems such as seizures and intellectual disability, ranging from mild to severe. Some people with beta-ureidopropionase deficiency have no neurological symptoms, and the disorder can only be diagnosed with laboratory testing.

The mutations that cause beta-ureidopropionase deficiency reduce or eliminate beta-ureidopropionase enzyme activity. Loss of this enzyme function reduces the production of beta-aminoisobutyric acid and beta-alanine, and leads to an excess of their precursor molecules, N-carbamyl-beta-aminoisobutyric acid and N-carbamyl-beta-alanine, which are released in the urine. Reduced production of beta-aminoisobutyric acid and beta-alanine may impair their functions in the nervous system, leading to neurological problems in some people with beta-ureidopropionase deficiency. The extent of the reduction in enzyme activity caused by a particular UPB1 gene mutation, along with other genetic and environmental factors, may determine whether people with beta-ureidopropionase deficiency develop neurological problems and the severity of these problems.

Where is the UPB1 gene located?

Cytogenetic Location: 22q11.2

Molecular Location on chromosome 22: base pairs 24,494,467 to 24,528,390

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBIThis link leads to a site outside Genetics Home Reference.)

The UPB1 gene is located on the long (q) arm of chromosome 22 at position 11.2.

The UPB1 gene is located on the long (q) arm of chromosome 22 at position 11.2.

More precisely, the UPB1 gene is located from base pair 24,494,467 to base pair 24,528,390 on chromosome 22.

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

Where can I find additional information about UPB1?

You and your healthcare professional may find the following resources about UPB1 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 UPB1 gene or gene products?

  • beta-alanine synthase
  • beta-ureidopropionase
  • BUP1
  • n-carbamoyl-beta-alanine amidohydrolase

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding UPB1?

alanine ; ammonia ; breakdown ; deficiency ; disability ; DNA ; dopamine ; enzyme ; gene ; inflammation ; mutation ; nervous system ; neurological ; precursor ; protein ; pyrimidines ; RNA

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

See also Understanding Medical Terminology.

References (6 links)


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: August 2014
Published: February 1, 2016