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Genetics Home Reference: your guide to understanding genetic conditions
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MT-TE

Reviewed October 2012

What is the official name of the MT-TE gene?

The official name of this gene is “mitochondrially encoded tRNA glutamic acid.”

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

What is the normal function of the MT-TE gene?

The MT-TE gene provides instructions for making a molecule called a transfer RNA (tRNA), which is a chemical cousin of DNA. Transfer RNAs help assemble protein building blocks (amino acids) into functioning proteins. The MT-TE gene provides instructions for making a specific form of tRNA that is designated as tRNAGlu. During protein assembly, this molecule attaches to the amino acid glutamic acid (Glu) and inserts it into the appropriate locations in the growing protein.

The tRNAGlu molecule is present only in cellular compartments called mitochondria. These structures convert energy from food into a form that cells can use. Through a process called oxidative phosphorylation, mitochondria use oxygen, simple sugars, and fatty acids to create adenosine triphosphate (ATP), the cell's main energy source. The tRNAGlu molecule is involved in the assembly of proteins that carry out oxidative phosphorylation.

In certain cells in the pancreas, called beta cells, mitochondria also play a role in controlling the amount of sugar (glucose) in the bloodstream. In response to high glucose levels, mitochondria help trigger the release of a hormone called insulin. Insulin regulates blood sugar levels by controlling how much glucose is passed from the blood into cells to be converted into energy.

Does the MT-TE gene share characteristics with other genes?

The MT-TE gene belongs to a family of genes called TRNA (transfer RNAs).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.

How are changes in the MT-TE gene related to health conditions?

maternally inherited diabetes and deafness - caused by mutations in the MT-TE gene

A mutation in the MT-TE gene has been found in a small number of people with maternally inherited diabetes and deafness (MIDD). People with this condition have diabetes and sometimes hearing loss, particularly of high tones. Affected individuals may also have muscle weakness (myopathy) and problems with their eyes, heart, or kidneys. The mutation involved in this condition replaces the DNA building block (nucleotide) thymine with the nucleotide cytosine at position 14709 (written as T14709C). This mutation likely impairs the ability of mitochondria to help trigger insulin release. In affected individuals, diabetes results when the beta cells do not produce enough insulin to regulate blood sugar effectively. Researchers have not determined how the T14709C mutation leads to hearing loss or the other features of MIDD.

other disorders - caused by mutations in the MT-TE gene

Mutations in the MT-TE gene are also involved in infantile transient mitochondrial myopathy (also known as benign COX deficiency myopathy). This rare condition occurs within the first few months of life and causes severe muscle weakness, poor muscle tone (hypotonia), and buildup of a chemical called lactic acid in the body (lactic acidosis). Affected infants often have difficulty feeding and need support from a machine to help them breathe. The signs and symptoms improve after several months, and most affected individuals show no symptoms of the condition by age 2 or 3.

The mutations involved in infantile transient mitochondrial myopathy change single nucleotides in mitochondrial DNA. Specifically, the nucleotide thymine at position 14674 is replaced by the nucleotide cytosine or guanine (written as T14674C or T14674G, respectively). These mutations impair oxidative phosphorylation. As a result, muscle cells cannot produce enough energy, leading to the muscle problems that affect infants with infantile transient mitochondrial myopathy. It is unknown why only muscles are involved or how affected infants recover from the condition.

Where is the MT-TE gene located?

The MT-TE gene is located in mitochondrial DNA.

Molecular Location in mitochondrial DNA: base pairs 14,673 to 14,741

Overview of gene located on mitochondrial DNA Close-up of gene located on mitochondrial DNA

Where can I find additional information about MT-TE?

You and your healthcare professional may find the following resources about MT-TE 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 MT-TE gene or gene products?

  • MTTE
  • trnE

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding MT-TE?

acidosis ; acids ; adenosine triphosphate ; amino acid ; ATP ; benign ; cell ; cytosine ; deficiency ; diabetes ; DNA ; fatty acids ; gene ; Glu ; glucose ; glutamic acid ; guanine ; hormone ; hypotonia ; inherited ; insulin ; lactic acid ; lactic acidosis ; mitochondria ; molecule ; muscle cells ; muscle tone ; mutation ; nucleotide ; oxidative phosphorylation ; oxygen ; pancreas ; phosphorylation ; protein ; RNA ; thymine ; transfer RNA ; transient ; tRNA

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Horvath R, Kemp JP, Tuppen HA, Hudson G, Oldfors A, Marie SK, Moslemi AR, Servidei S, Holme E, Shanske S, Kollberg G, Jayakar P, Pyle A, Marks HM, Holinski-Feder E, Scavina M, Walter MC, Coku J, Günther-Scholz A, Smith PM, McFarland R, Chrzanowska-Lightowlers ZM, Lightowlers RN, Hirano M, Lochmüller H, Taylor RW, Chinnery PF, Tulinius M, DiMauro S. Molecular basis of infantile reversible cytochrome c oxidase deficiency myopathy. Brain. 2009 Nov;132(Pt 11):3165-74. doi: 10.1093/brain/awp221. Epub 2009 Aug 31. (http://www.ncbi.nlm.nih.gov/pubmed/19720722?dopt=Abstract)
  • Mezghani N, Mkaouar-Rebai E, Mnif M, Charfi N, Rekik N, Youssef S, Abid M, Fakhfakh F. The heteroplasmic m.14709T>C mutation in the tRNA(Glu) gene in two Tunisian families with mitochondrial diabetes. J Diabetes Complications. 2010 Jul-Aug;24(4):270-7. doi: 10.1016/j.jdiacomp.2009.11.002. Epub 2010 Jan 4. (http://www.ncbi.nlm.nih.gov/pubmed/20045353?dopt=Abstract)
  • Mimaki M, Hatakeyama H, Komaki H, Yokoyama M, Arai H, Kirino Y, Suzuki T, Nishino I, Nonaka I, Goto Y. Reversible infantile respiratory chain deficiency: a clinical and molecular study. Ann Neurol. 2010 Dec;68(6):845-54. doi: 10.1002/ana.22111. (http://www.ncbi.nlm.nih.gov/pubmed/21194154?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/4556)
  • Rigoli L, Prisco F, Caruso RA, Iafusco D, Ursomanno G, Zuccarello D, Ingenito N, Rigoli M, Barberi I. Association of the T14709C mutation of mitochondrial DNA with maternally inherited diabetes mellitus and/or deafness in an Italian family. Diabet Med. 2001 Apr;18(4):334-6. (http://www.ncbi.nlm.nih.gov/pubmed/11437868?dopt=Abstract)
  • Uusimaa J, Jungbluth H, Fratter C, Crisponi G, Feng L, Zeviani M, Hughes I, Treacy EP, Birks J, Brown GK, Sewry CA, McDermott M, Muntoni F, Poulton J. Reversible infantile respiratory chain deficiency is a unique, genetically heterogenous mitochondrial disease. J Med Genet. 2011 Oct;48(10):660-8. doi: 10.1136/jmg.2011.089995. (http://www.ncbi.nlm.nih.gov/pubmed/21931168?dopt=Abstract)
  • Vialettes BH, Paquis-Flucklinger V, Pelissier JF, Bendahan D, Narbonne H, Silvestre-Aillaud P, Montfort MF, Righini-Chossegros M, Pouget J, Cozzone PJ, Desnuelle C. Phenotypic expression of diabetes secondary to a T14709C mutation of mitochondrial DNA. Comparison with MIDD syndrome (A3243G mutation): a case report. Diabetes Care. 1997 Nov;20(11):1731-7. (http://www.ncbi.nlm.nih.gov/pubmed/9353617?dopt=Abstract)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: October 2012
Published: July 21, 2014