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 <i>SPG20</i> gene (13q13.1), which encodes the protein spartin.
Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed.
Troyer syndrome: a combination of central brain abnormality and motor neuron disease?
Auer-Grumbach M, Fazekas F, Radner H, Irmler A, Strasser-Fuchs S, Hartung HP. J Neurol. 1999;246(7):556-61.
A variant with the additional features of severe atrophy of the small hand muscles, dysarthria, mental retardation, and short stature has been termed Troyer syndrome (MIM#275900) after the name of Old Order Amish families suffering from these symptoms.