Fibrodysplasia ossificans progressive is a disease in which muscle tissue and connective tissue such as tendons and ligaments are replaced by bone (ossified). This is a gradual process that generally begins in early childhood, starting at the neck and shoulders, eventually spreading to the limbs constricting movement. Once loss in joint mobility begins, those affected by this disease may be unable to use their mouth which leads to malnutrition. Difficulty breathing occurs when the extra bone forms around the rib cage. Any trauma caused to the muscles of someone with Fibrodysplasia ossificans progressive, including falls and invasive procedures, can trigger the ossification to the injured area. Viral infections such as influenza can also cause flare ups in the muscle with result in ossification.
Fibrodysplasia ossificans progressive is a very rare disease. The estimates are approximately 1 in 2 million people worldwide have this condition. Only several hundred cases of the disease have been reported. This disease is rare because it is caused by the genetic mutation in the ACVR1 gene. ACVR1 provides the instructions for the producing member of the protein family called bone morphogenetic protein type 1 receptors. ACVR1 is found in many tissues which include skeletal muscle and cartilage. Its role is to help control the growth and development of bones and muscles. This includes the gradual ossification that occurs normally from birth to adulthood.
Researchers believe that a mutation in the ACVR1 gene may change the shape of the receptor in which disrupts the mechanism that controls the receptor’s activity. The constitutive activation of the receptor causes overgrowth of bone and cartilage as well as the fusion of joint. This condition is inherited in an autosomal dominant pattern. Most cases of Fibrodysplasia ossificans progressive are caused by a new mutation unseen in the family’s previous history.
Article used: http://ghr.nlm.nih.gov/condition/fibrodysplasia-ossificans-progressiva
Related Article: http://news.discovery.com/human/genetics/what-causes-rare-disease-that-hardens-tissue-into-bone-150904.htm