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Start free with EleplanAdenylosuccinate synthetase-like 1-related distal myopathy
ORPHA:482601Disease
Also called ADSSL1-related distal myopathy
What it is
A rare autosomal recessive distal myopathy characterized by slowly progressive diffuse muscle weakness in childhood, followed by predominantly distal muscle weakness in adolescence, and quadriceps muscle weakness in the fourth decade. Facial muscle weakness is commonly reported. Muscle biopsy shows fiber size variation, increased internal nuclei, fiber splitting, rimmed vacuoles, and focal endomysial fibrosis.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Adolescent, Childhood
- 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
Very common80–99%
3Common30–79%
23- Ankle contracture
- Difficulty climbing stairs
- Difficulty running
- Distal lower limb amyotrophy
- Distal lower limb muscle weakness
- Distal upper limb muscle weakness
- Elbow contracture
- Fatigable weakness of chewing muscles
- Foot dorsiflexor weakness
- Generalized amyotrophy
- Internally nucleated skeletal muscle fibers
- Lower limb amyotrophy
- Proximal muscle weakness in lower limbs
- Quadriceps muscle atrophy
- Quadriceps muscle weakness
- Reduced forced vital capacity
- Reduced tendon reflexes
- Restrictive ventilatory defect
- Rimmed vacuoles
- Tip-toe gait
- Triceps weakness
- Upper limb amyotrophy
- Weakness of facial musculature
Sometimes5–29%
8These 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.
Benefit programs to look at
Programs whose eligibility touches the same ICD-10 categories. Eligibility is decided by the administering agency, never by this page.
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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