U.S. flag

An official website of the United States government

GTR Home > Conditions/Phenotypes > Mitochondrial DNA depletion syndrome, myopathic form

Mitochondrial DNA depletion syndrome, myopathic form

Synonyms
MITOCHONDRIAL DNA DEPLETION MYOPATHY, TK2-RELATED; MITOCHONDRIAL DNA DEPLETION SYNDROME 2 (MYOPATHIC TYPE); Mitochondrial DNA depletion syndrome 2; TK2-Related Mitochondrial DNA Depletion Syndrome, Myopathic Form
Modes of inheritance
Autosomal recessive inheritance (Orphanet)

Summary

Excerpted from the GeneReview: TK2-Related Mitochondrial DNA Maintenance Defect, Myopathic Form
TK2-related mitochondrial DNA (mtDNA) maintenance defect is a phenotypic continuum that ranges from severe to mild. To date, approximately 107 individuals with a molecularly confirmed diagnosis have been reported. Three main subtypes of presentation have been described: Infantile-onset myopathy with neurologic involvement and rapid progression to early death. Affected individuals experience progressive muscle weakness leading to respiratory failure. Some individuals develop dysarthria, dysphagia, and/or hearing loss. Cognitive function is typically spared. Juvenile/childhood onset with generalized proximal weakness and survival to at least 13 years. Late-/adult-onset myopathy with facial and limb weakness and mtDNA deletions. Some affected individuals develop respiratory insufficiency, chronic progressive external ophthalmoplegia, dysphagia, and dysarthria.
Full text of GeneReview (by section):
Summary
Diagnosis
Clinical Characteristics
Genetically Related (Allelic) Disorders
Differential Diagnosis
Management
Genetic Counseling
Resources
Molecular Genetics
Chapter Notes
References
Authors:
Julia Wang
Ayman W El-Hattab
Lee-Jun C Wong
view full author information

Available tests

73 tests are in the database for this condition.

Check Related conditions for additional relevant tests.

Clinical tests (73 available)

Molecular Genetics Tests

Genes See tests for all associated and related genes

  • Also known as: MTDPS2, MTTK, PEOB3, SCA31, TK2-EXT, TK2
    Summary: thymidine kinase 2

Clinical features

Help
Imported from Human Phenotype Ontology (HPO)

Show allHide all

IMPORTANT NOTE: NIH does not independently verify information submitted to the GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in the GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.