Fibrodyplasia Ossificans Progressiva is an extremely rare genetic disorder in which muscles, tendons, ligaments and other connective tissues in the body turn into bones. Throughout the aging process, FOP eventually causes permanent immobility of the body, with people unable to move or bend the affected areas of the body. This debilitating disease, although rare, is life-threatening and must be cured. Although scientists are now able to identify the cause, more research is needed to fully understand the cause and create an effective treatment. This medical abnormality is so rare that only recently has a cause been identified. After fifteen years of research, orthopedic surgeon Frederick Kaplan, MD of the University of Pennsylvania, his research team found the faulty gene responsible for the mutation (“Fibrodysplasia Ossificans Progressiva”). Mutation of the ACVR1 gene causes fibrodysplasia ossificans progressive. The ACVR1 gene is found in many tissues, including skeletal muscle and cartilage. It plays a role in the growth of bones and muscles. It is also involved in bone formation from birth to adulthood, particularly in the transition from cartilage to bone. The gene can cause changes in specific bone receptors. These are the receptors that turn bone formation on and off. Mutation of the gene causes constant activation of the receptor; this causes the bones to overgrow over the cartilage. fuse and bony sheaths form over other bones (“ACVR1”). The disease is extremely rare, affecting around 1 in 1.6 million people worldwide. No proven correlation between age, race, gender, ethnicity or geographic location. One of the first documented...... middle of article...... ibrodysplasia Ossificans Progressiva. " Clinical Reviews in Bone and Mineral Metabolism. Vol. 3. Humana, 2005. 252-54. PDF file. Kaplan, Frederick. "The phenotype of fibrodysplasia ossificans progressiva" Clinical Reviews in Bone and Mineral Metabolism Vol. Skeleton of the FOP." FOP skeleton. 2009. Web. April 15, 2014. .Kaplan, Frederick. “An Historical Perspective” clinical examinations of bone and mineral metabolism. Flight. 3. Humana, 2005. 179-80. PDF file.Kaplan, Frederick S. et al. “Early diagnosis of fibrodysplasia ossificans progressiva”. Pediatrics 121.5 (2008): e1295-e1300. University of California - San Francisco. “Study highlights consequences of poor medical diagnosis.” ScienceDaily, November 8. 2005. .