Novel polymerase gamma (POLG1) gene mutation in the linker domain associated with parkinsonism

Mutations in the POLG1 gene have variable phenotypic presentations and a high degree of clinical suspicion is necessary for their recognition. Parkinsonism and ataxia are the most common movement disorders associated with POLG1 mutations but no phenotype-genotype correlation has been established.

We identified a male patient with progressive external ophthalmoplegia who also developed a progressive bradykinesia, rigidity and camptocormia in the third decade. Parkinsonism was partially responsive to dopaminegic replacement. His father and brother had reportedly similar clinical problems. Genetic analysis identified a novel mutation p.K512M in the POLG1 gene.

This report further expands the spectrum of POLG1-associated neurologic problems with the report of a novel mutation in the linker region of the gene, which are rarely associated with parkinsonism.