Mitochondrial deoxyribonucleoside triphosphate pools in thymidine kinase 2 deficiency

Biochem Biophys Res Commun. 2003 Oct 24;310(3):963-6. doi: 10.1016/j.bbrc.2003.09.104.


Deficiency of mitochondrial thymidine kinase (TK2) is associated with mitochondrial DNA (mtDNA) depletion and manifests by severe skeletal myopathy in infancy. In order to elucidate the pathophysiology of this condition, mitochondrial deoxyribonucleoside triphosphate (dNTP) pools were determined in patients' fibroblasts. Despite normal mtDNA content and cytochrome c oxidase (COX) activity, mitochondrial dNTP pools were imbalanced. Specifically, deoxythymidine triphosphate (dTTP) content was markedly decreased, resulting in reduced dTTP:deoxycytidine triphosphate ratio. These findings underline the importance of balanced mitochondrial dNTP pools for mtDNA synthesis and may serve as the basis for future therapeutic interventions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / metabolism
  • DNA, Mitochondrial / metabolism
  • Deoxyribonucleotides / metabolism*
  • Electron Transport Complex IV / metabolism
  • Fibroblasts / metabolism
  • Homozygote
  • Humans
  • Mitochondria / metabolism*
  • Mitochondrial Myopathies / pathology
  • Mutation
  • Thymidine Kinase / deficiency*


  • DNA, Mitochondrial
  • Deoxyribonucleotides
  • Electron Transport Complex IV
  • thymidine kinase 2
  • Thymidine Kinase