How PABPN1 Fails in OPMD
It’s thought that in OPMD the defective gene that carries the instructions for PABPN1 is defective and causes the protein to form clumps in the cell nuclei thus interfering with the functions of the cell. When seen under a microscope the muscle tissue from OPMD patients shows protein inclusions in the nuclei along with bubble looking structures in muscle cells. The gene contains DNA known as the GCN, which repeats ten times. When the gene is defective as in OPMD the repeats happen at a rate of eleven to seventeen times forming the clumped sections that can be seen under a microscope and resulting in the alanine protein that can’t be broken down. These clumps inhibit cell function and over time cause the muscle cells to weaken and die.