Late-onset thymidine kinase 2 deficiency: a review of 18 cases.

ABSTRACT:

Background

TK2 gene encodes for mitochondrial thymidine kinase, which phosphorylates the pyrimidine nucleosides thymidine and deoxycytidine. Recessive mutations in the TK2 gene are responsible for the 'myopathic form' of the mitochondrial depletion/multiple deletions syndrome, with a wide spectrum of severity.

Methods

We describe 18 patients with mitochondrial myopathy due to mutations in the TK2 gene with absence of clinical symptoms until the age of 12.

Results

The mean age of onset was 31 years. The first symptom was muscle limb weakness in 10/18, eyelid ptosis in 6/18, and respiratory insufficiency in 2/18. All patients developed variable muscle weakness during the evolution of the disease. Half of patients presented difficulty in swallowing. All patients showed e

SUBMITTER: Dominguez-Gonzalez C 

PROVIDER: S-EPMC6501326 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature