What is Pompe Disease?
Pompe disease is a rare inherited disease named after Johannes Pompe, the doctor who first described its characteristics. This disorder affects the muscles, contributing to deterioration of muscle strength. Although it was first spotted in an infant, it can affect people of all ages.
What causes Pompe disease?
Pompe disease is a genetic disorder that affects the level of the enzyme acid alpha-glucosidase. This enzyme acts to prevent a build up of glycogen in the muscles and without it, the muscles become weak. In people with Pompe disease, either the levels of the enzyme are low, the enzyme is missing completely or it does not function properly. The result is a build-up of glycogen in the muscles, which affects strength and muscle tone.
The gene in question is the GAA gene. In people with Pompe disease, this gene is defective and this affects the production and function of acid alpha-glucosidase.
Pompe disease is an inherited condition, which means that is passed down to children by their parents. A person would inherit Pompe disease if they inherited the defective gene from each parent.
What are the symptoms of Pompe disease?
Symptoms of Pompe disease are associated with a build-up of glycogen in the muscle tissue and include:
- weakness in the muscles in the upper and lower limbs
- difficulty doing physical tasks and exercise
- breathing difficulties (especially when lying down)
In infants, it is also common for Pompe disease to cause severe lack of muscle strength and tone and an enlarged heart, which may lead to breathing difficulties and delayed development.
The symptoms of Pompe disease can affect people in different way. Some people have more severe symptoms than others and the effects can be diverse, from making it hard for a baby to breathe to making it increasingly difficult for a middle-aged woman to climb the stairs.
In most cases, the symptoms of Pompe disease progress with time. Symptoms tend to develop rapidly in small children and more gradually in older people.
What is the prognosis for Pompe disease?
The prognosis varies according to the age of the individual and the nature and severity of their symptoms. Typically, infants tend to struggle and many die before they reach their first birthday. In older children and adults, the symptoms tend to be less severe and they progress at a slower rate.
How is Pompe disease diagnosed?
It can be difficult to diagnose Pompe disease as it is so complex and it causes diverse symptoms. Many of the symptoms are also associated with other illnesses or disorders. If a doctor suspects an individual may have Pompe disease, they can carry out tests to confirm a diagnosis. Tests that can be useful include blood tests, X-rays, an echocardiogram (ECG) and breathing tests. Tests can also be done to assess the function of the muscles. One of the most important tests is a blood test to monitor the levels and activity of the enzyme.
Are there any treatment options?
There is currently no cure for Pompe disease, but there are treatments to help to alleviate symptoms and prolong life. Enzyme replacement therapy can be used to boost levels of the GAA enzyme and this usually has a positive effect on symptoms. Other therapies, such as physiotherapy, can help to improve mobility and reduce pain.
Patients diagnosed with Pompe disease are referred for treatment by a specialist care team made up of a group of health professionals with varied areas of expertise. The aim is to provide solutions for the diverse range of issues presented by this complex disorder. Examples of treatments include:
- occupational therapy
- exercises to make breathing easier
- nutritional guidance
- heart monitoring