Mutations in the nuclear gene encoding the catalytic subunit of mitochondrial DNA polymerase gamma-1 (
POLG1) are associated with phenotypically heterogeneous neurological manifestations. Among adult
POLG-1-associated mitochondrial diseases, the predominant clinical features are chronic progressive external ophthalmoplegia, sensory ataxic neuropathy, dysarthria/dysphagia (SANDO syndrome), Parkinsonism [
1]. Hereditary spastic paraplegias (HSPs) consist of a group of neurodegenerative disorders involving the corticospinal tracts with clinico-genetic heterogeneity. Complex HSP forms involve additional neurologic features, while pure forms of HSP are characterized by isolated slowly progressive lower limb spasticity and weakness [
2‐
5]. …