Dystonia Responsive to Dopamine: POLG Mutations Should Be Considered If Sensory Neuropathy Is Present
The POLG gene encodes mitochondrial DNA polymerase, and mutations in this gene cause a spectrum of disorders related to mitochondrial DNA depletion or deletion. Dystonia has only rarely been reported as an early and prominent manifestation of POLG mutations. We report a case of a 30-year-old male presenting with lower limb dystonia with peripheral neuropathy and demonstrate that the dystonia was levodopa responsive (with video findings). Whole-genome sequencing revealed biallelic variants in the POLG gene: a known pathogenic variant [NM_001126131.2:c.2209G>C (p.Gly737Arg)] and a novel likely pathogenic variant [NM_001126131.2:c.3305A>C (p.Gln1102Pro)]. A genetic diagnosis was made before the appearance of more readily recognizable features of mitochondrial disease, allowing us to avoid invasive tissue biopsies or potentially deleterious treatments, such as sodium valproate. A POLG-related disorder should be suspected in cases of dystonia with peripheral neuropathy, and this diagnosis may have implications for further investigations and management.
|ISBN||2005-940X (Print) 2005-940X (Linking)|
|Authors||Qiu, J.; Kumar, K. R.; Watson, E.; Ahmad, K.; Sue, C. M.; Hayes, M. W.|
|Responsible Garvan Author||Dr Kishore Kumar|
|Publisher Name||Journal of Movement Disorders|
|URL link to publisher's version||https://www.ncbi.nlm.nih.gov/pubmed/34062649|