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ALAS1

ALAS1

Aminolevulinate, delta-, synthase 1

What is the normal function of the ALAS1 gene?

The ALAS1 gene produces an enzyme called delta-aminolevulinate synthase 1 (ALA-synthase). ALAS1 is one of two genes that carry the information for the production of this enzyme. The other gene that makes ALA-synthase is ALAS2, which is only turned on in red blood cells. ALA-synthase is produced by ALAS1 in all tissues of the body; it is especially important in the liver, where it is used in the production of heme (the oxygen-carrying part of hemoglobin). ALA-synthase is also used to make other hemoproteins, enzymes that process drugs and chemicals, and enzymes that produce energy.

ALA-synthase carries out the first step in the production of heme. Each of the steps in heme production is controlled by a separate gene (see below). The first step in this process is the synthesis of delta-aminolevulinic acid (ALA). Seven other enzymes will modify ALA before it actually becomes heme. The activity of ALA-synthase determines how much heme the tissues in the body will produce.

The following genes are part of the chemical pathway for making heme.

  • ALAD:aminolevulinate, delta-, dehydratase
  • ALAS1:aminolevulinate, delta-, synthase 1
  • ALAS2:aminolevulinate, delta-, synthase 2 (sideroblastic/hypochromic anemia)
  • CPOX:coproporphyrinogen oxidase (coproporphyria, harderoporphyria)
  • FECH:ferrochelatase (protoporphyria)
  • HMBS:hydroxymethylbilane synthase
  • PPOX:protoporphyrinogen oxidase
  • UROD:uroporphyrinogen decarboxylase
  • UROS:uroporphyrinogen III synthase (congenital erythropoietic porphyria)

What conditions are related to the ALAS1 gene?

Researchers have not yet identified any conditions associated with the ALAS1 gene.

Where is the ALAS1 gene located?

3p21.1

The ALAS1 gene is located on the short (p) arm of chromosome 3 at position 21.1.

The ALAS1 gene is located on the short (p) arm of chromosome 3 at position 21.1.

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

Where can I find information about ALAS1?

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

What other names do people use for the ALAS1 gene or gene products?

  • ALASH
  • ALAS, housekeeping type
  • ALA-synthase
  • 5-aminolevulinate synthase
  • Delta-ALA synthetase
  • Delta-aminolevulinate synthase
  • HEM1_HUMAN

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.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding ALAS1?

anemia ; congenital ; enzyme ; gene ; heme ; hemoglobin ; oxygen ; red blood cell ; synthesis ; synthetase

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

 
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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.
 
Last Comprehensive Review: June 2004
Updated: June 29, 2004
Published: October 8, 2004
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