Lysosomes are small compartments within the cells in your body. They are sometimes referred to as the ‘recycling centres’ of the cell. They contain enzymes which help to break down and digest different substances, others go on to be recycled by the cell. If there is a problem with one of the enzymes in the lysosome, substances are not digested or recycled properly and build up, causing damage to the cells and organs. Individually these disorders are rare, but collectively it is thought they affect around 1 person in every 7,700 births.