About Facioscapulohumeral Muscular Dystrophy
FSHD is caused by contraction of the D4Z4 repeat region on chromosome 4q35, which normally has 11-150 repeats. Individuals with fewer than 11 repeats have FSHD1. In FSHD1, the smaller repeat array leads to aberrant chromatin opening and expression of the normally silenced DUX4 gene. DUX4 produces a toxic transcription factor that triggers a cascade of molecular events including oxidative stress, abnormal gene expression, cellular apoptosis, and inflammation. FSHD2 results from mutations in epigenetic regulators like SMCHD1 that affect D4Z4 methylation. Both pathways converge on DUX4 ectopic expression in muscle.
FSHD shows distinctive asymmetric weakness pattern, often manifesting first in facial muscles with difficulty smiling or closing eyes completely, followed by shoulder girdle weakness with characteristic scapular winging. Upper arm muscles weaken more than forearms, and lower extremities are affected in 20% of patients with advanced disease. Disease progression is highly variable, with some patients remaining stable for years while others progress rapidly to significant disability. About 20% of FSHD patients become severely disabled, requiring wheelchairs. Pain syndromes are common and can precede weakness. Respiratory involvement is unusual but possible in advanced disease.
Common Symptoms of Facioscapulohumeral Muscular Dystrophy
Recognizing the signs of Facioscapulohumeral Muscular Dystrophy early can lead to faster diagnosis and better outcomes. Symptoms may vary in severity from person to person. If you or a loved one are experiencing any of the following, consider speaking with a specialist.
- Progressive weakness of facial muscles affecting ability to smile or close eyes
- Shoulder weakness and winging of scapula
- Upper arm weakness and difficulty lifting arms overhead
- Asymmetric weakness pattern, often starting on one side
- Difficulty with stairs and walking in later stages
- Pain in shoulders and upper back
Who Facioscapulohumeral Muscular Dystrophy Affects
FSHD1 typically manifests in adolescence or early adulthood (mean age 15-20 years), though can appear in childhood or much later. FSHD2 generally has later onset. Affects males and females equally. Autosomal dominant inheritance with high penetrance but variable expressivity. Can occur in any ethnicity.
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Help Paying for Facioscapulohumeral Muscular Dystrophy Treatment
Charity funds and drugmaker programs for Facioscapulohumeral Muscular Dystrophy, checked at the source. Pick your insurance to see what fits.
- From a charity · Muscular Dystrophy AssociationMDA Durable Medical Equipment (DME) Grant Program fundApply directly
Pays for: Medical equipment (wheelchairs, lifts, canes and other DME), up to $1,000 per year.
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Side Effect Explorer
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Genetic Testing
Genetic testing can confirm a diagnosis, guide treatment decisions, and identify family members who may be at risk.
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Trusted Facioscapulohumeral Muscular Dystrophy Resources
Reputable organizations and medical references for learning more about Facioscapulohumeral Muscular Dystrophy, including disease registries, foundation resources, and clinical guidelines.