Abstract
The authors measured the absolute amount of mitochondrial DNA (mtDNA) within single muscle fibers from two patients with thymidine kinase 2 (TK2) deficiency and two healthy controls. TK2 deficient fibers containing more than 0.01 mtDNA/microm3 had residual cytochrome c oxidase (COX) activity. This defines the minimum amount of wild-type mtDNA molecules required to maintain COX activity in skeletal muscle and provides an explanation for the mosaic histochemical pattern seen in patients with mtDNA depletion syndrome.
Publication types
-
Research Support, N.I.H., Extramural
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Adult
-
DNA, Mitochondrial / genetics*
-
Electron Transport Complex IV / metabolism
-
Energy Metabolism / genetics*
-
Female
-
Gene Dosage / genetics*
-
Humans
-
Infant
-
Mitochondrial Myopathies / genetics*
-
Mitochondrial Myopathies / metabolism
-
Mitochondrial Myopathies / physiopathology
-
Muscle Fibers, Skeletal / metabolism
-
Muscle Fibers, Skeletal / pathology
-
Muscle, Skeletal / metabolism*
-
Muscle, Skeletal / pathology
-
Muscle, Skeletal / physiopathology
-
Predictive Value of Tests
-
Reference Values
-
Succinate Dehydrogenase / metabolism
-
Thymidine Kinase / deficiency*
Substances
-
DNA, Mitochondrial
-
Succinate Dehydrogenase
-
Electron Transport Complex IV
-
thymidine kinase 2
-
Thymidine Kinase