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Start free with EleplanAutosomal recessive spastic paraplegia type 20
ORPHA:101000Disease
Also called Childhood-onset spastic paraparesis-distal muscle wasting syndrome · SPG20 · Troyer syndrome
What it is
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.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Infancy
- Inheritance
- Autosomal recessive
- Classified as
- Disease
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Common30–79%
30- Abnormal cerebellum morphology
- Abnormal foot morphology
- Abnormal hand morphology
- Abnormality of brain morphology
- Abnormality of the hand
- Abnormality of the skeletal system
- Babinski sign
- Cognitive impairment
- Constipation
- Delayed speech and language development
- Dysarthria
- Dysphagia
- Dysuria
- Generalized hypotonia
- Global developmental delay
- Growth delay
- Hyperreflexia
- Hypertelorism
- Impaired vibratory sensation
- Joint hypermobility
- Motor delay
- Overbite
- Short stature
- Skeletal muscle atrophy
- Slurred speech
- Spastic dysarthria
- Spasticity
- Spastic paraparesis
- Specific learning disability
- Upper limb muscle weakness
Sometimes5–29%
21- Abnormality of the nares
- Abnormal thumb morphology
- Ankle clonus
- Anxiety
- Clinodactyly
- Distal amyotrophy
- Downslanted palpebral fissures
- Emotional lability
and 13 more in this range
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Gene
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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