Pompe disease is a rare genetic disorder caused by a deficiency of the enzyme acid alpha-glucosidase (GAA), leading to an abnormal accumulation of glycogen in various tissues of the body. The most visible accumulation is in the muscles. This condition can manifest in two distinct forms: infantile-onset Pompe disease and late-onset Pompe disease, often referred to as IOPD and LOPD.
Infantile-onset Pompe disease presents in early infancy and is characterized by severe and rapidly progressive muscle weakness, cardiac involvement, and respiratory issues. Late-onset Pompe disease typically manifests later in life, often during childhood, adolescence, or adulthood. It has milder and more variable progression of symptoms, primarily affecting the skeletal muscles and respiratory system. While both forms share the same underlying genetic cause, their clinical presentations and prognoses differ significantly.
Enlargement of the heart (cardiomegaly) tends to be more commonly associated with infantile-onset Pompe disease. In infantile-onset Pompe disease, the heart is often significantly affected, leading to cardiac complications at an early age. Although this can be seen in late-onset Pompe disease, it is not nearly as common.