Central core disease (CCD) is a genetic condition that affects the muscles. It’s part of a group of muscle conditions called congenital myopathies. These conditions are usually present at birth or early childhood and lead to muscle weakness.
CCD is named after the unusual areas seen in the centre of muscle fibres when looked at under a microscope.
In most cases, symptoms can be noticed at birth or shortly after. However, sometimes the symptoms are mild and may not be noticed for several years. The heart and breathing muscles are usually not affected in people with CCD but might be in severe cases and should be monitored if needed.
Muscle weakness in people with CCD mainly affects the muscles closest to the centre of the body, such as those in the hips, upper legs, shoulders, and upper arms. Initial symptoms include floppiness or hypotonia (low muscle tone). Children are often delayed in reaching motor milestones, such as sitting unaided and walking. Muscle cramps, stiffness, and fatigue are also common. In severe cases, muscles may shrink (muscle wasting), which can lead to worsening muscle weakness with age. CCD usually doesn’t cause facial weakness, especially around the eyes, unlike some other types of congenital myopathies.
Weakness is mainly around the hips, which can lead to hip dislocations or contractures (joint tightness), particularly in the knees and hips. People may also develop foot deformities and, in some cases, scoliosis (curvature of the spine). This may require corrective surgery, which can further affect mobility and posture.
CCD is caused by changes in the RYR1 gene, which provides instructions to make the RYR1 protein, essential for muscle function and contraction. When we move, our muscles contract and relax in a coordinated way. Changes in the RYR1 gene disrupt this process, leading to unusual muscle development and weakness.
The RYR1 gene is also linked to another congenital myopathy called multiminicore disease (MmD). Changes in the RYR1 gene can also cause a condition known as malignant hyperthermia (MH). This is a potentially life-threatening reaction to certain anaesthetics and muscle relaxants.
CCD is usually inherited in an autosomal dominant pattern, meaning only one changed gene is needed to cause it. In rare cases, CCD can be inherited in an autosomal recessive pattern where both parents pass down a changed gene. Sometimes, a genetic change may happen for the first time in a person with no family history of the condition.
For more information, see our inheritance and genetics page.
A GP can refer a child to a paediatrician to investigate symptoms. A paediatrician is a doctor who specialises in treating babies, children, and young people. If needed, the paediatrician can then refer the child to a neurologist, a doctor that specialises in conditions affecting the muscles and nervous system.
The neurologist will carry out a physical assessment and may recommend further tests, such as a muscle MRI, muscle biopsy, or genetic testing, to come to a diagnosis.
In a muscle biopsy, a small sample of muscle is taken and examined under a microscope. Usually, muscle tissue has two types of fibres, type 1 and type 2, in roughly equal amounts. People with CCD will have type 1 muscle tissue fibres with damaged areas called central cores.
Genetic testing, using a blood sample, can check for changes in the RYR1 gene to confirm CCD. As genetic testing becomes more advanced, some people may receive a diagnosis without needing a muscle biopsy. Instead, they may be given a diagnosis of RYR1-related myopathy if a change in the RYR1 gene is found.
Once the gene change has been identified in one family member, it’s possible to use this sequence to diagnose other family members and unaffected carriers. The genetic changes in the RYR1 gene that cause CCD can vary significantly. This means the symptoms of CCD can also vary.
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. This involves different healthcare professionals working together.
People with CCD should have access to a multidisciplinary 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.
Physiotherapy and mild exercise are encouraged to maintain muscle strength and mobility. It can also maintain breathing capacity and slow the progression of contractures. A physiotherapist is a healthcare professional who helps manage symptoms through movement, exercise, and manual therapy. They can put together a suitable exercise plan to follow. Recommended exercises include swimming, walking, and pedalling, as these aerobic exercises can help maintain a healthy cardiovascular system and a steady weight. Before starting any new form of exercise, it’s important to discuss it first with a clinician. Excessive exercise can lead to ‘exercise induced myalgia’, which is muscle pain that occurs after too much or intense exercise and should be avoided. For advice for adults, see exercising with a muscle wasting condition.
Orthopaedic management may be needed to manage joint contractures or scoliosis. The type of orthopaedic management will depend on the person’s particular needs. This can include using splints, braces, and other tailored orthotic devices. Surgery may also be needed. Orthopaedic management refers to the treatment and care of bones, joints, and muscles.
For scoliosis, spinal surgery may be necessary to realign the spine. It’s important to discuss all options with a specialist.
Anaesthesia stops a person feeling pain during a procedure or surgery. Before any medical procedure, it’s important to make the anaesthetist and other healthcare professionals aware of a diagnosis of CCD, as well as any heart or breathing complications. This will help them plan for specific needs and ensure safety. Those with a change in the RYR1 gene are at particularly high risk of a severe reaction known as malignant hyperthermia.
Malignant hyperthermia (MH) is a potentially life-threatening reaction, triggered by the use of certain general anaesthetics and muscle relaxants. Conditions with changes in the RYR1 gene, such as CCD, increase a person’s risk of developing MH.
Symptoms of MH include a rapid rise in body temperature, rigidity of muscles or spasms, rapid heart rate (tachycardia), muscle breakdown (rhabdomyolysis), and dark brown urine due to broken down muscle entering the bloodstream and urine (myoglobinuria). MH must be treated immediately with a drug called Dantrolene, whilst also attempting to cool the person’s body temperature.
MH can be prevented by avoiding triggering anaesthetic agents and using alternative drugs. Suxamethonium (succinylcholine) must be avoided. It’s crucial that the clinical team is made aware of the condition if surgery under general anaesthetics is needed, so that alternative options can be considered.
Author: Muscular Dystrophy UK
Reviewers: Dr Vasantha Gowda and Dr Imelda Hughes
Last reviewed: March 2025
Next review due: March 2028
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