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Start free with EleplanHNRNPA1-related adult-onset distal myopathy
ORPHA:399086Disease
Also called Distal myopathy type 3 · Finnish upper limb-onset distal myopathy · MPD3
What it is
Finnish upper limb-onset distal myopathy is a rare, genetic distal myopathy characterized by slowly progressive distal to proximal limb muscle weakness and atrophy, with characteristic early involvement of thenar and hypothenar muscles. Patients present with clumsiness of the hands and stumbling in the fourth to fifth decade of life, and later develop steppage gait and contractures of the hands. Progressive fatty degeneration affects intrinsic muscles of the hands, gluteus medium and both anterior and posterior compartment muscles of the distal lower extremities, with later involvement of forearm muscles, triceps, infraspinatus and the proximal lower limb muscles. Asymmetry of muscle involvement is common.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Adult
- Classified as
- Disease
Recorded for the broader condition
- Inheritance
- Autosomal dominantAutosomal dominant distal myopathy
Orphanet records these for the broader condition rather than for this specific form. They are a starting point, not a figure for this subtype — subtypes often differ, and some are defined by being rarer than the condition they sit under.
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%
13- Amyotrophy of ankle musculature
- Clumsiness
- Distal sensory impairment
- EMG: myopathic abnormalities
- Fatty replacement of skeletal muscle
- Gait disturbance
- Intrinsic hand muscle atrophy
- Joint contracture of the hand
- Mildly elevated creatine kinase
- Progressive distal muscle weakness
- Rimmed vacuoles
- Steppage gait
- Weakness of the intrinsic hand muscles
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.
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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