Living With MPS VI The MPS VI Community is now on Facebook! Make friends, share your ideas, plans and hopes on how to live with MPS VI. Click here to join the "Living with MPS VI" group on Facebook . MPS VI is a rare but serious genetic disease. Only about 1100 people in the world have it. Also known as Maroteaux-Lamy, MPS VI is a result of a missing or malfunctioning enzyme that is necessary to break down waste products called GAG in cells. Over time, GAG builds up in the cells and results in damage and malfunction of major organs and symptoms. Learn more on MPSVI.com.