Monarch Disease Ontology entry MONDO_0010156 (Troyer syndrome) can be described as follows. Autosomal recessive spastic paraplegia type 20 (SPG20) is a type of complex hereditary spastic paraplegia characterized by an onset in infancy of progressive spastic paraparesis associated with distal amyotrophy, psuedobulbar palsy, motor and cognitive delays, mild cerebellar signs (dysarthria, dysdiadochokinesia, mild intention tremor), short stature and subtle skeletal abnormalities (pes cavus, mild talipes equinovarus, kyphoscoliosis). SPG20 is due to mutations in the SPG20 gene (13q13.1), which encodes the protein spartin. Also known as: SPG20, autosomal recessive spastic paraplegia 20, autosomal recessive spastic paraplegia Troyer type, autosomal recessive spastic paraplegia type 20, childhood-onset spastic paraparesis with distal muscle wasting, childhood-onset spastic paraparesis-distal muscle wasting syndrome, hereditary spastic paraplegia 20, spastic paraplegia 20 (Troyer syndrome).