Facioscapulohumeral muscular dystrophy (FSHD)

Facioscapulohumeral muscular dystrophy (FSHD) is a genetic condition that causes progressive muscle weakness. This means muscles get weaker over time. It mainly affects the face, shoulders, and upper arms. Symptoms usually become noticeable in early adulthood, though they may appear later if mild.

There are two types of FSHD:

• FSHD type 1: This is the most common type, making up 95 out of 100 cases of FSHD. It’s caused by a change in the D4Z4 region on chromosome 4.
• FSHD type 2: This rarer form is linked to changes in the SMCHD1 gene, which affects the D4Z4 region. In FSHD type 2, there is no genetic change in the D4Z4 region itself.

Early-onset FSHD is a rare subtype of FSHD that begins in childhood. Almost all cases are FSHD type 1. Children with early-onset FSHD tend to have a more rapidly progressive weakness and have additional health issues.

The symptoms and severity of FSHD vary greatly, even between family members with the condition. Some may experience only mild symptoms throughout their lives; others may have more significant challenges. Symptoms are similar for both types of FSHD.

Face, shoulder and upper-arm weakness

Muscle weakness in FSHD typically affects:

• The face – weakness in facial muscles can make it difficult to close the eyes completely or purse the lips. In cases of severe facial weakness, speech and the ability to display typical emotional expressions can be affected.
• The shoulders – weakness around the shoulders can make it difficult to lift the arms above shoulder height. It may cause scapular winging (when the shoulder blades rise and stick out more).
• Upper arms

One side of the body may be affected more than the other.

Lower-limb, posture and mobility changes

At a later stage of the condition, some people may experience weakness in:

• The torso and spine – this will affect posture and can lead to lumbar lordosis (the exaggerated inward curve of the spine).
• Leg muscles – weakness in the lower legs can cause foot drop (difficulty raising the foot), making climbing stairs and walking on uneven surfaces difficult.

People with FSHD:

• May have a backward-leaning and high-stepping style of walking.
• May be prone to falls because of reduced balance.
• Some may eventually require a wheelchair, especially for longer distances.

Pain

People with FSHD often have chronic musculoskeletal pain, especially in the neck, shoulders, and lower back. This is indirectly caused by muscle weakness in FSHD.

Breathing and respiratory symptoms

Most people with FSHD do not have significant breathing issues. Respiratory function is usually well maintained in FSHD.

However, about 1 in 10 people with FSHD have some weakness in the chest wall muscles, which can affect lung function.

Weakness of the diaphragm and expiratory muscles can lead to reduced lung function and a weak cough.

Overnight breathing problems are uncommon but may result in daytime sleepiness, morning headaches, poor appetite, and weight loss. Around 1 in 100 people require overnight ventilatory support.

In people with FSHD, a gene called DUX4 is mistakenly switched on. This causes the DUX4 protein to be made and build-up in muscle cells. This build up is harmful and causes inflammation, damage and weakness.

The DUX4 gene is switched on in different ways in each type of FSHD.

People with FSHD type 1 have fewer than normal DNA repeats in the D4Z4 region on chromosome 4. These repeats normally act as a block to keep the DUX4 gene turned off. With fewer repeats, this block becomes weaker, allowing the DUX4 gene to switch on and produce DUX4 protein.

In FSHD type 2, a change in the SMCHD1 gene on chromosome 18 switches on the DUX4 gene, leading to similar muscle damage and symptoms.

FSHD can be inherited or developed.

FSHD is usually inherited in an autosomal dominant pattern. This means that only one copy of the changed gene is needed from either parent to have the condition.

In some cases, a person with FSHD has not inherited the condition from either of their parents. Instead, the genetic change occurred spontaneously. This is called a de novo genetic change.

For more information, see our inheritance and genetics page.

A GP can make a referral to a neurologist for testing if there are signs of a muscle wasting condition. A neurologist is a doctor specialising in diagnosing, treating, and managing conditions that affect the muscles and nervous system.

Diagnosis of FSHD typically involves a combination of physical examination, family history, and genetic testing. In most cases, FSHD can be confirmed using a blood test.

For more information, see our diagnosis page.

Symptoms, age of onset, and severity vary from person to person, and so management will be tailored to an individual’s needs.

Treatments for FSHD are being tested in clinical trials. We, at Muscular Dystrophy UK, are funding research to try and find treatment options for FSHD.

Specialist support and follow-up

A multi-disciplinary approach is important in the treatment of Pompe disease. This means different healthcare professionals work together to manage the condition and symptoms and improve wellbeing.

People with FSHD should have access to a multi-disciplinary healthcare team. Usually, the lead professional will be a neurologist. If you do not have contact with a neurologist or specialist doctor, speak to your GP about getting access to one.

Exercise and physiotherapy

Staying active is important. Regular activity and exercise can help manage pain and maintain the muscle strength of non-affected or minimally affected muscles. This may also help people to stay independent for longer.

Specialist physiotherapists can provide advice on healthy activities and suitable exercise. A physiotherapist is a healthcare professional who helps manage symptoms through movement, exercise, and manual therapy. Physiotherapists can help create a suitable exercise plan and provide advice on posture and fatigue management.

After exercise, allow time to fully recover the next day. Some muscle soreness is okay, but this should not be severe pain and should improve over time. To find out more about advice for adults, see exercising with a muscle wasting condition.

Orthotics, mobility and posture

Orthotic devices are supports or braces used to help manage muscle weakness, assist with walking, and support posture. Common options include:

• Ankle-foot orthoses (AFOs) to manage foot drop
• Shoulder supports to manage scapular winging

These can be prescribed by an orthotics team after referral from a GP or specialist. Orthotics services need to be contacted again if supports and braces are uncomfortable or do not fit properly so that adjustments can be made.

Eyes, speech and respiratory monitoring

If those affected are unable to fully close eyelids while sleeping, it can lead to dry eyes. In severe cases, this can lead to corneal ulcers. Using eye lubricants can protect the eyes and prevent irritation. These issues can be discussed with the healthcare team and regular eye checks are recommended.

If facial weakness begins to affect speech, a speech and language therapist can carry out an assessment. Speech therapy can help people improve their speech clarity and communication skills. This may include exercises to strengthen speech muscles, techniques to improve articulation, or strategies to make up for speech difficulties.

As some people experience respiratory weakness, it’s important to monitor respiratory function with forced vital capacity (FVC) testing at review appointments. Overnight sleep studies may also be necessary to assess breathing during sleep. Chest infections should always be treated promptly. If necessary, cough augmentation techniques and chest physiotherapy may be recommended.

Early-onset FSHD, also called infantile or childhood-onset FSHD, is a form of FSHD that typically starts before the age of 10. It usually progresses more quickly and is more severe. It causes muscle weakness and wasting, usually affecting the face, shoulders, and upper arms first, and causes additional health issues. Generally, the earlier symptoms start, the more severe the condition will be.

Symptoms of early-onset FSHD

Muscle weakness and wasting is the primary symptom. It often begins in the face and shoulders. It can include:

• Facial weakness – difficulty closing the eyes, whistling, or showing typical facial expressions. The face may look thin or expressionless.
• Shoulder weakness – difficulty lifting the arms and scapular winging (when the shoulder blades rise and stick out more).
• Weakness in the arms and legs – this can make climbing stairs, getting up from a chair, or walking difficult. People sometimes develop foot drop (difficulty lifting the foot and toes).

Muscle weakness can progress rapidly. Children may have trouble walking or running. Some may eventually lose the ability to walk on their own. A wheelchair may be needed by the time of adolescence or early adulthood.

Other possible symptoms include:

• Hearing loss – this is common and can worsen over time.
• Eye problems – problems with the blood vessels in the retina can occur and potentially affect vision.
• Breathing difficulties – weakness of the breathing muscles is possible, though less common.
• Heart problems – these are rare but can occur.
• Asymmetrical weakness – one side of the body may be weaker than the other, especially early on.
• Curved spine – the spine may develop a sideways curve (scoliosis) or inward curve (lordosis).
• Learning and behaviour – some children may experience mild learning or behavioural challenges.
• Pain and fatigue – muscle pain and tiredness are common.

The severity of early-onset FSHD can vary widely, even among family members with the condition.

How is early-onset FSHD managed?

A multi-disciplinary approach is needed to manage early-onset FHSD. This means different healthcare teams working together. Support focuses on symptom relief and maximising quality of life. Because of the faster progression of early-onset FSHD, children are likely to need medical support as soon as symptoms appear. A team of specialists, including neurologists, physiotherapists, audiologists, ophthalmologists, orthopaedic surgeons, and genetic counsellors, is crucial.

Treatment and support include:

• Muscle weakness – exercise, assistive devices (such as braces or wheelchairs), and possibly medication for pain or fatigue.
• Pain – pain management techniques, including medication if needed.
• Fatigue – strategies to save energy and assistive devices to make movement easier.
• Hearing loss – hearing aids or surgery to improve hearing.
• Vision Problems – regular eye exams and treatment if needed.
• Scoliosis – bracing or surgery, depending on severity.
• Additional support includes nutritional guidance and emotional support.

Regular check-ups with the healthcare team are essential to monitor changes and adjust care as needed.