What are the main symptoms of Pompe disease?
Pompe disease is caused by a missing enzyme in the lysosomes, which are like the recycling center of the cell. Missing this enzyme leads to build up of glycogen in muscle cells which damages the muscle cells. Muscle cell damage leads to weakness of the muscles needed to move the body (skeletal muscles), pump the heart (cardiac muscles), and move the lungs for breathing (respiratory muscles). The weakness gets worse over time.
In infantile onset Pompe disease (IOPD), the symptoms can start in the newborn period or even before a baby is born. The heart gets bigger than it is supposed to be and has more trouble pumping blood, called cardiomyopathy.
In late onset Pompe disease (LOPD), the heart is usually not involved, but the muscles the body uses to help the lungs move air in and out of the body (the diaphragm) becomes weak. Patients have slowly progressing symptoms and may not recognize they are somewhat unsteady on their feet, have trouble getting out of a chair into a standing position, even holding a blowdryer to dry your hair. Often it's a loved one or someone close to a patient that may recognize the symptoms. Muscles affected first are those proximal (closest to the body) and then weakness travels to distal muscles (further away from the body). Shoulders, upper arms, pelvic area, and thighs are often first affected. Limb girdle muscles involving the pelvic and thighs are most often affected.
The only currently available treatment for either IOPD or LOPD is enzyme replacement therapy, in which a man-made version of acid alpha-glucosidase is infused into the body through a vein every two weeks. Over time, this enzyme breaks down the glycogen which has built up. It helps the heart get smaller and work better in IOPD. It helps people with IOPD and LOPD get better muscle strength. However, enzyme replacement therapy must be given every 2 weeks for the rest of a person's life. Other treatments are being studied in clinical trials as well.
Babies with Pompe disease are often diagnosed based upon the symptoms seen at birth, but later onset Pompe disease may be more difficult to diagnose and require the involvement of multiple doctors who specialize in areas such as neurology (the nervous system) and metabolics (how the body turns food into energy). The best person to help figure out if someone has Pompe disease is their main doctor, who can then order testing or make referrals to the appropriate specialists.