Imagine that, on your way to work, you slip and fall on a patch of ice on the sidewalk. Now imagine that, instead of just getting a bruise, your body responds to the injury by turning the muscles, tendons, and ligaments you hurt into bone -- forever crippling your ability to move that part of your body.
This is the fate of those with fibrodysplasia ossificans progressiva (FOP), one of the rarest, most disabling genetic conditions, in which inflammation causes the body's soft tissues to turn to bone, slowly trapping victims in a second skeleton.
Ashley Kurpiel, 28, from Peachtree City, Ga., has battled FOP since she was diagnosed at age 3 -- just five months after doctors mistakenly amputated her right arm, on the assumption that the growths caused by FOP were cancerous tumors.
"Ninety percent of [FOPers] get misdiagnosed with some form of cancer," Kurpiel says.
Some undergo needless chemotherapy, biopsies, or surgeries, all of which worsen the condition -- causing more inflammation and consequently, more bone.
There are believed to be 700 patients with FOP around the globe. For them, something as simple as a visit to the dentist, a fall, or an immunization shot can lead the joints to lock up -- sometimes overnight -- never to move again.
"I can't move my left arm from my side at all, I have very little neck movement, no lower back movement at all, my right hip is affected, and my upper back is really stiff," Kurpiel says.
The condition slowly freezes up the victim's body, but trauma, infection, or any cause for inflammation can speed the progression, precipitating a painful flare-up and leading to further bone growth and disability.
"The worst flare-up I had was my upper thigh at age 25. The whole leg was red and swollen, I couldn't move, it was insanely painful," Kurpiel says.
Currently there is "no real treatment to cure or significantly change the course of the disease," says Dr. Eileen Shore, a research associate professor of orthopedic surgery at the University of Pennsylvania, who has studied the disease since 1991.
Steroids can be administered at the first signs of a flare-up to reduce the inflammation, but the success of this treatment is limited and varies greatly from patient to patient, Shore says.
While the fate of FOPers may seem bleak, there is much reason to hope, says Dr. Fred Kaplan, an orthopedist who has devoted his life to solving the mysterious genetic disorder.
Since the identification of the gene, which causes FOP, in 2006 "we are in a whole different universe" in the research, Kaplan says. "It opened up new horizons of therapy and unlocked the doors of hope."
Muscles spontaneously turning into bone may sound like science fiction, but researchers now understand that it is the work of a single genetic mutation that causes the body's inflammation response to run amok.
At birth, FOP may show up as a deformity of the big toes and sometimes extra bones in the neck, but extra bone formation elsewhere usually begins in the first decade of life, Kaplan says.
FOPers feel a flare-up coming on when a particular body part becomes stiff, red, swollen, and painful -- indicating that an inflammation response is occurring. During this response, signals get crossed: instead of producing new healthy soft tissue to heal the injury, the body begins making hard tissue -- pushing out healthy muscles and ligaments in the process.