If one gene in the pair is abnormal, the normal gene takes over. The person is unaffected by the disease but is a carrier.
Every person carries abnormal genes.
The problem arises when both autosomal genes in the pair are abnormal. Symptoms of AMD . AMD is caused by a build up of glycogen in the muscle cells. Glycogen is a thick, sticky substance that is converted from sugars and starches and is stored in the muscle cells for future use. Acid maltase enzyme breaks down the unused glycogen in the muscle cells.