SPG11 and cerebellar ataxia: Apart from age of onset, our analysis revealed numerous phenotypic features that help differentiating SPG7 and SPG11. Individuals with SPG7 are more likely to develop ataxia, extraocular movement disturbances and seizure, whereas those with SPG11 more commonly experience parkinsonism, dystonia, peripheral neuropathy, dysphagia, retinopathy/optic nerve atrophy, cognitive, and mood impairment.