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


Reviewed July 2011

What is the official name of the MUT gene?

The official name of this gene is “methylmalonyl-CoA mutase.”

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

What is the normal function of the MUT gene?

The MUT gene provides instructions for making an enzyme called methylmalonyl CoA mutase. This enzyme is active in mitochondria, which are specialized structures inside cells that serve as energy-producing centers.

Methylmalonyl CoA mutase is responsible for a particular step in the breakdown of several protein building blocks (amino acids), specifically isoleucine, methionine, threonine, and valine. The enzyme also helps break down certain types of fats (lipids) and cholesterol. First, several chemical reactions convert the amino acids, lipids, or cholesterol to a molecule called methylmalonyl CoA. Then, working with a compound called adenosylcobalamin (AdoCbl), which is a form of vitamin B12, methylmalonyl CoA mutase converts methylmalonyl CoA to a compound called succinyl-CoA. Other enzymes break down succinyl-CoA into molecules that are later used for energy.

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

methylmalonic acidemia - caused by mutations in the MUT gene

More than 200 mutations in the MUT gene have been identified in people with methylmalonic acidemia, a condition characterized by feeding difficulties, developmental delay, and long-term health problems. These genetic changes prevent the production of functional methylmalonyl CoA mutase or reduce the activity of the enzyme. As a result, certain proteins and lipids are not broken down properly. This defect allows methylmalonyl CoA and other toxic compounds to build up in the body's organs and tissues, causing the signs and symptoms of methylmalonic acidemia.

Mutations that prevent the production of any functional methylmalonyl CoA mutase lead to a form of methylmalonic acidemia designated mut0. Mut0 is the most severe form of this disorder and has the poorest outcome. Mutations that alter the structure of the enzyme but do not completely eliminate its activity lead to a form of the condition designated mut-. The mut- form is typically less severe, with more variable symptoms than the mut0 form.

Where is the MUT gene located?

Cytogenetic Location: 6p12.3

Molecular Location on chromosome 6: base pairs 49,430,360 to 49,463,328

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

The MUT gene is located on the short (p) arm of chromosome 6 at position 12.3.

The MUT gene is located on the short (p) arm of chromosome 6 at position 12.3.

More precisely, the MUT gene is located from base pair 49,430,360 to base pair 49,463,328 on chromosome 6.

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

Where can I find additional information about MUT?

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

  • MCM
  • methylalonyl-CoA mutase
  • methylamlony-CoA isomerase
  • methylmalonyl CoA mutase
  • methylmalonyl Coenzyme A mutase
  • methylmalonyl Coenzyme A mutase precursor

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

What glossary definitions help with understanding MUT?

acids ; breakdown ; cholesterol ; CoA ; coenzyme A ; compound ; developmental delay ; enzyme ; gene ; isoleucine ; methionine ; mitochondria ; molecule ; precursor ; protein ; threonine ; toxic ; valine ; vitamin B12

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


  • Acquaviva C, Benoist JF, Pereira S, Callebaut I, Koskas T, Porquet D, Elion J. Molecular basis of methylmalonyl-CoA mutase apoenzyme defect in 40 European patients affected by mut(o) and mut- forms of methylmalonic acidemia: identification of 29 novel mutations in the MUT gene. Hum Mutat. 2005 Feb;25(2):167-76. (
  • Benoist JF, Acquaviva C, Callebaut I, Guffon N, Ogier de Baulny H, Mornon JP, Porquet D, Elion J. Molecular and structural analysis of two novel mutations in a patient with mut(-) methylmalonyl-CoA deficiency. Mol Genet Metab. 2001 Feb;72(2):181-4. (
  • Chandler RJ, Venditti CP. Genetic and genomic systems to study methylmalonic acidemia. Mol Genet Metab. 2005 Sep-Oct;86(1-2):34-43. Epub 2005 Sep 22. Review. (
  • Fuchshuber A, Mucha B, Baumgartner ER, Vollmer M, Hildebrandt F. mut0 methylmalonic acidemia: eleven novel mutations of the methylmalonyl CoA mutase including a deletion-insertion mutation. Hum Mutat. 2000 Aug;16(2):179. (
  • Gene Review: Isolated Methylmalonic Acidemia (
  • Hörster F, Baumgartner MR, Viardot C, Suormala T, Burgard P, Fowler B, Hoffmann GF, Garbade SF, Kölker S, Baumgartner ER. Long-term outcome in methylmalonic acidurias is influenced by the underlying defect (mut0, mut-, cblA, cblB). Pediatr Res. 2007 Aug;62(2):225-30. (
  • NCBI Gene (
  • Peters HL, Nefedov M, Lee LW, Abdenur JE, Chamoles NA, Kahler SG, Ioannou PA. Molecular studies in mutase-deficient (MUT) methylmalonic aciduria: identification of five novel mutations. Hum Mutat. 2002 Nov;20(5):406. (
  • Worgan LC, Niles K, Tirone JC, Hofmann A, Verner A, Sammak A, Kucic T, Lepage P, Rosenblatt DS. Spectrum of mutations in mut methylmalonic acidemia and identification of a common Hispanic mutation and haplotype. Hum Mutat. 2006 Jan;27(1):31-43. (


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: July 2011
Published: February 8, 2016