What causes Pompe disease?

Pompe disease is a rare condition that can affect males and females of all ages and ethnic backgrounds. It is also a ‘genetic’ condition, which means it is passed through families from parents to their children.

Pompe disease can cause a range of health problems, but the most common sign is muscle weakness that gets worse over time if left untreated. You may also hear Pompe disease called a ‘metabolic disorder’. ‘Metabolic’ is the word used to describe the chemical processes that take place in the body..

There is no cure for Pompe disease, but treatment to manage the symptoms and progression of the disease is available.

Other names for Pompe disease

You may see Pompe disease called one or more of the following, but they are all exactly the same condition:

  • Acid maltase deficiency (AMD)
  • Glycogen storage disease (GSD) type II
  • Glycogenosis type II
  • Acid alpha-glucosidase deficiency

What causes Pompe disease?

Enzymes are substances produced by cells in the body, which help chemical reactions take place. There are many different enzymes, which have different actions and allow the body to function normally.

One of the enzymes that the body normally makes is called ‘acid alpha-glucosidase’ – or ‘GAA’ for short. GAA helps to break down a substance called glycogen. Pompe disease is a condition in which the body does not make enough GAA. This is a problem, because a lack of GAA means that glycogen cannot be broken down as it normally would be, so it builds up in the cells of the body, especially in muscle cells. Over time, this build‐up can damage muscles, so they don’t work as well as they once did. If the damaged muscles are in the legs, for example, then walking will become harder than usual. The same is true for the lungs. If the muscles that help the lungs to work are affected, then breathing will become more difficult.

The body is made up of very tiny building blocks called ‘cells’. The part of the cell in which glycogen builds‐up and is stored in is called the ‘lysosome’. Pompe disease is therefore called a ‘lysosomal storage disorder’.

Pompe disease – build-up of glycogen in cells due to lack of GAA

Pompe disease is a:

  • Genetic disorder (passed down from parents to children)
  • Neuromuscular disorder (affects the working of muscles)
  • Metabolic disorder (affects chemical processes in cells)
  • Lysosomal storage disorder (the lysosome is the part of the cell where glycogen builds up)