U.S. researchers have taken a huge leap towards the goal to demolish the anarchy of the FOP – a connective tissue disorder in which bone grows in tendons, ligaments, and muscles; by discovering a defective gene responsible for one of the rarest and most disastrous inherited diseases affecting humans.
Scientists at the University Of Pennsylvania School Of Medicine told Sunday that they have discovered a mutant gene that triggers the body to form a second, renegade skeleton, solving the mystery of a rare disease called FOP that imprisons children in bone for life.
FOP – Fibrodysplasia Ossificans Progressiva is a rare disease of the connective tissue. A mutation of the body’s repair mechanism causes fibrous tissue, including tendons, ligaments, and muscles to become bony when damaged. These painful bony growths develop slowly over a period of weeks or months, usually beginning in the upper back and shoulders. In many cases they can cause joints to become permanently frozen in place.
The disorder begins in childhood to increasingly transform muscles, ligaments and tendons into ribbons, sheaths and plates of bone that cover and lock the joints, making movement impossible.
Dr. Frederick Kaplan, an orthopedist whose team at the University Of Pennsylvania School Of Medicine pinpointed the cause of FOP – a rare disease that causes muscles and other connective tissues to turn into bone, imprisoning children for life in a second skeleton, “FOP is the most catastrophic disorder of extra skeletal ossification known to mankind.”
The genetic freakishness occurs in only one in two million children, with an estimated 2,500 people worldwide. The discoverers have identified nearly 600 children and adults with the condition, including a fistful in Canada.
Scientists at the University of Pennsylvania and international colleagues, after spending 15 years on work involving study of the genetic makeup of multigenerational families around the world, found that FOP is caused by a single mutation in a gene called ACVR1 – which they discovered in a region of chromosome 2. This annihilating bug means that tendons, ligaments and skeletal muscle begin painfully transforming into bone, sometimes locking joints overnight.
Kaplan, in a telephonic interview said that the genetic twist that leads to FOP “is relevant to every condition that affects the formation of bone and every condition that affects the formation of the skeleton.”
Dr. Victor A. McKusick, a genetics pioneer and professor of medical genetics at Johns Hopkins University School of Medicine in Baltimore, said, “In the next five years, this might open up the possibility of developing drugs that would be effective in stopping bone formation.” He further added that the FOP genetic breakthrough is expected to shed light on other related diseases.
FOP sufferer Jeannie Peeper, 47, of Winter Springs, Fla., said, “The gene discovery is an extraordinary gift to the FOP community and a monumental milestone on our road to a cure.” The disease has left her totally immobilized wheelchair-bound and totally dependent on others for care. However, she continues as a leader of the International FOP Association that represents patients and their families.
Kaplan and his collaborators’ findings, reported in the online edition of the journal Nature Genetics with contributions from researchers in Australia, Brazil, France, Germany, Great Britain, the Netherlands and South Korea, of genetic mutation that causes FOP, are hopefully setting the stage not only to treat the rare bone disorder, but more common bone buildup related to head and spine trauma, and even sports injuries.