Emery-Dreifuss muscular dystrophy (EDMD)

Emery-Dreifuss muscular dystrophy (EDMD) is a group of inherited conditions that cause slowly progressive muscle weakness and wasting, joint tightness (contractures), and problems with the heart’s electrical conduction system. There are several different genetic changes that can cause EDMD, so symptoms can vary.

Different types of EDMD:

• EDMD type 1 – caused by a change in the EMD gene.
• EDMD type 2 – caused by a change in the LMNA/C gene. Previously called limb girdle muscular dystrophy 1B (LGMD1B). This condition is no longer classified as a limb girdle muscular dystrophy.
• X-linked EDMD – caused by a change in the FHL1 gene.

Symptoms usually develop during childhood or adolescence.

Contractures

The first noticeable symptom may be stiffness in various joints, such as the ankles, neck, or elbows. This stiffness is known as contractures. People will often walk on tiptoes because their ankles are tight, and they may struggle to fully bend or straighten their arms. Although contractures themselves are not painful, they can make sitting or walking uncomfortable and some people report muscle pain in their legs.

Muscle weakness

Most people will develop muscle weakness and wasting of the calves, shoulders, and arms. In some people, this weakness can also affect the thigh and hip muscles. EDMD progresses slowly over many years, but walking can become increasingly difficult, and some people will need to use a wheelchair.

Respiratory

Breathing muscles can also be affected, particularly as weakness progresses. This can cause poor sleep leading to fatigue, morning headaches, or daytime sleepiness. There is an increased risk of chest infections.

Cardiac

The heart problems in EDMD are mostly due to ‘conduction defects’, which means a disruption in the electrical signals that guide the heart to pump at the right time. This can cause abnormal heart rhythms (arrhythmia), which may result in breathlessness, tiredness, or palpitations (a fluttering feeling in the chest). These problems require close monitoring, as they can put people at risk of sudden death. Heart issues could be asymptomatic, so regular monitoring is crucial. See the cardiac monitoring section below for more information. Because of heart problems, people with EDMD may have a shortened life expectancy.

Genetic changes

EDMD is a genetic condition, so a person develops it when they inherit genetic changes from their parents. Changes can be in one of several genes including LMNA/C, EMD and FHL1. There are also people with the condition where the gene causing the problem has not been found, and so more genes may be added to this list in future.

Inheritance

For people with LMNA/C, EMD or FHL1 mutations, the way the condition is passed on depends on which gene is affected.

Changes in the LMNA/C gene are passed on in an autosomal dominant inheritance pattern. This means only one gene change – passed down from either parent – is needed to cause the condition. The parent who passed on the gene will also have the condition. People with LMNA/C changes have a 1 in 2 chance of passing the condition on to their own children. This is because the child will inherit only one copy of the LMNA/C gene from the affected parent and has a 1 in 2 chance of inheriting either the changed gene or a healthy copy.

Occasionally, the change happens for the first time in the affected person rather than being passed down from their parent. This is called a de-novo mutation. De-novo mutations can still be passed on to the affected person’s children.

Changes in EMD and FHL1 are passed on in an X-linked recessive inheritance pattern. These genes are found on a section of DNA called the X chromosome. Men have only one X chromosome and women have two. If someone inherits a change in the EMD or FHL1 gene, how it affects them depends on whether they are male or female.

• In males, they will not have another working copy of the gene, because men always only have one X chromosome, so they will develop the condition.
• In females, they are very likely to have a working copy of the gene on their second or ‘spare’ X chromosome, so they typically do not have the condition. Women with one changed copy are called carriers.

This means that when a female carrier has children, there is a 1 in 2 chance of them passing the gene change on to each child.

• If a carrier passes on the change and the child is a boy, then that boy will have full EDMD.
• Men with EDMD caused by changes in the EMD or FHL1 genes will not have affected children. This is because they do not pass on their X chromosome on to male children.
• However, their female children will almost certainly be carriers.

Carriers usually do not have symptoms, but rarely they can have some of the heart problems or mild muscle weakness. This may require regular monitoring.

For more information, see our inheritance and genetics page.

A GP can refer to a neurologist – a doctor who specialises in diagnosing, treating, and managing conditions that affect the muscles and nervous system. The neurologist may come to a diagnosis using a combination of physical examination, blood tests, and genetic testing. Sometimes, muscle biopsy or muscle MRI are recommended.

Often, the doctor will notice contractures but relatively strong muscles. A blood test usually shows high levels of creatine kinase (CK), which suggests muscle damage. A muscle biopsy can show damage within the muscle and whether any of three important proteins are missing or in the wrong place. A Muscle MRI scan can show which muscles are affected and if the pattern matches other cases of EDMD. However, these results can also be seen in other neuromuscular conditions.

A diagnosis of EDMD can be confirmed by identifying a change in one of the genes known to cause the condition. This is done by analysing DNA from a blood sample. It’s possible there are gene changes that can also cause EDMD but have not yet been identified.

For more information, see our diagnosis page.

A multi-disciplinary approach is important in not only managing the condition and symptoms but in improving wellbeing too.

Access to a healthcare team

People with EDMD should have access to a multi-disciplinary healthcare team – a team of healthcare professionals working together. 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. It is also important to see a cardiologist regularly for heart monitoring.

Cardiac monitoring

Heart problems are common in EDMD and can be symptomless. It’s important to have regular heart monitoring appointments with a cardiologist. Tests such as an electrocardiogram (ECG), echocardiogram (ECHO), and Holter monitoring may be required. Female carriers of EDMD should also be offered heart monitoring. The cardiologist may prescribe medication to protect the heart or recommend a small device, such as a pacemaker or implantable cardioverter defibrillator (ICD). These devices help manage irregular heart rhythms. In cases of severe heart problems (severe cardiomyopathy), a heart transplant may be necessary.

For more information, see our heart page.

Respiratory monitoring

Breathing problems can develop in EDMD, particularly as muscle weakness progresses. 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. Breathing exercises, cough assist devices, and non-invasive ventilation may be recommended to support respiratory function if it is needed.

For more information, see our breathing page.

Exercise and physiotherapy

Staying active and maintaining strength is important for people with EDMD. A physiotherapist can work with you to create a suitable exercise plan.

Keeping mobile helps keep your joints flexible and muscles as strong as possible. It’s important to do the right amount and type of exercise. In general, it’s recommended to exercise regularly, but aim to feel fully recovered by the day after. Some mild muscle soreness is okay, but exercise should not cause pain or weakness that limits your everyday activities.

Exercise can help in three main ways:

• Keeping your joints and muscles flexible

  This is done through stretching exercises, which target specific joint contractures (tightness) or improve overall mobility. Often, tightness can develop if the joints have more limited movement due to the weakness. It’s important to stretch regularly – ideally four to six times a week – to feel the benefits.

• Keeping your muscles as strong as possible

  Strengthening exercises involve working against resistance. This could include using your own body weight, resistance bands, or small weights. These exercises should allow you to do only a few repetitions (around 12 to 15). Aim to do strength training two to three times a week.

• Maintain your heart and lung response to exercise

  Aerobic exercise involves activities done for a longer period of time (around 45 minutes), at an effort level where it becomes too difficult to talk during it. Depending on your ability, this could involve walking, Nordic walking (a type of walking that uses poles to work your upper body as well as your legs), swimming, dancing, arm cycling, or driving a powered wheelchair. Aerobic activity is recommended three to four times a week.

We have exercise advice for children and for adults. Ask for specific advice from a specialist physiotherapist who will help you adjust your exercise plan to your current abilities.

Orthotics

EDMD can cause foot drop, which means it’s difficult to lift the foot and toes because of muscle weakness. This makes it harder to stop the foot from flapping down when walking, which can lead to trips and falls.

If you have foot drop, you might benefit from the use of orthotic to support your ankle and improve your walking. Orthotics can also help with other issues, like sore feet or knees after prolonged walking, shoulder or back pain, or issues with posture.

Ask your GP or specialist to refer you to a local orthotics team or specialist orthotist for an assessment.

People with EDMD are at a higher risk of complications during general anaesthesia. It’s crucial that the anaesthetist and surgical team are aware of a diagnosis of EDMD and any heart or breathing problems the person has.

Neck stiffness and jaw tightness can make it more difficult to insert a breathing tube (intubation) during the procedure. A pre-operative assessment and extended post-operative monitoring is necessary. Specialist neuromuscular clinics can be contacted for advice if needed.

For more information, see our anaesthetics page.