Monarch Disease Ontology term MONDO_0017917 (maternally-inherited spastic paraplegia) is a rare, genetic, complex hereditary spastic paraplegia disorder characterized by adulthood-onset of slowly progressive, bilateral, mainly lower limb spasticity and distal weakness associated with lower limb pain, hyperreflexia, and reduced vibration sense. Axonal neuropathy is frequently observed on electromyography and nerve conduction examination. Also known as: MT-ATP6-related mitochondrial spastic paraplegia, maternally-inherited SPG.