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mitochondrially encoded tRNA aspartic acid
Alt. symbolsMTTD
Other data
LocusChr. MT [1]

Mitochondrially encoded tRNA aspartic acid also known as MT-TD is a transfer RNA which in humans is encoded by the mitochondrial MT-TD gene.[1]


The MT-TD gene is located on the p arm of the mitochondrial DNA at position 12 and it spans 67 base pairs.[2] The structure of a tRNA molecule is a distinctive folded structure which contains three hairpin loops and resembles a three-leafed clover.[3]


The MT-TD gene encodes for a small transfer RNA (human mitochondrial map position 7518-7585) that transfers the amino acid aspartic acid to a growing polypeptide chain at the ribosome site of protein synthesis during translation.

Clinical significance[edit]

MT-TD mutations have been associated with complex IV deficiency of the mitochondrial respiratory chain, also known as the cytochrome c oxidase deficiency. Cytochrome c oxidase deficiency is a rare genetic condition that can affect multiple parts of the body, including skeletal muscles, the heart, the brain, or the liver. Common clinical manifestations include myopathy, hypotonia, and encephalomyopathy, lactic acidosis, and hypertrophic cardiomyopathy.[4] A patient with a 7526A>G mutation in the MT-TD gene exhibited gradually worsening symptoms of exercise intolerance, increased creatine kinase levels, sustained exercise leading to muscle pains and general malaise.[5] A patient with a 7543A>G mutation also exhibited symptoms of the disease.[6]


  1. ^ Anderson S, Bankier AT, Barrell BG, de Bruijn MH, Coulson AR, Drouin J, Eperon IC, Nierlich DP, Roe BA, Sanger F, Schreier PH, Smith AJ, Staden R, Young IG (April 1981). "Sequence and organization of the human mitochondrial genome". Nature. 290 (5806): 457–65. doi:10.1038/290457a0. PMID 7219534.
  2. ^ "MT-TD mitochondrially encoded tRNA aspartic acid [ Homo sapiens (human) ]".
  3. ^ "tRNA / transfer RNA | Learn Science at Scitable".
  4. ^ Reference, Genetics Home. "Cytochrome c oxidase deficiency". Genetics Home Reference. This article incorporates text from this source, which is in the public domain.
  5. ^ Other variants include Seneca S, Goemans N, Van Coster R, Givron P, Reybrouck T, Sciot R, Meulemans A, Smet J, Van Hove JL (August 2005). "A mitochondrial tRNA aspartate mutation causing isolated mitochondrial myopathy". American Journal of Medical Genetics. Part A. 137 (2): 170–5. doi:10.1002/ajmg.a.30854. PMID 16059939.
  6. ^ Shtilbans A, El-Schahawi M, Malkin E, Shanske S, Musumeci O, DiMauro S (September 1999). "A novel mutation in the mitochondrial DNA transfer ribonucleic acidAsp gene in a child with myoclonic epilepsy and psychomotor regression". Journal of Child Neurology. 14 (9): 610–3. doi:10.1177/088307389901400910. PMID 10488907.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.