Doctors Thought This Teen Had Cancer at 16. Her Real Diagnosis Was Even Rarer

At 16, Holly LaPrade was living an ordinary teenage life. She had just gotten her driver’s license, started a part-time job, and joined her school’s basketball team. Then her body began to change, and doctors told her it might be cancer. She was ready to start chemotherapy. But cancer was not the answer, and the real answer was far rarer. Now 45, she is sharing her story to raise awareness.

The first signs were small. LaPrade says her shoulders, neck, and back felt stiff, and she could no longer lift her arms over her head. A friend noticed she could not turn her neck from side to side. Then seven areas on her body appeared to be tumors. Her mother took her to the hospital, where she was first thought to have non-Hodgkin lymphoma and met with an oncologist.

A biopsy showed it was not cancer, but no one knew what it was. After a week in the hospital, she got an answer: fibrodysplasia ossificans progressiva, or FOP. It is a rare genetic condition that grows bone in muscles, tendons, and other soft tissue. LaPrade had never heard of it. What stuck with her was that it was “not a death sentence.” She still had a lot to learn.

FOP Affects About 1 in 2 Million People, So Even Doctors Rarely See It

FOP turns soft tissue into bone. The condition is caused by a change in a gene called ACVR1. Over time, bone can form in muscles, tendons, and ligaments, forming what experts at Penn Medicine call a second skeleton that traps the body. The condition is progressive, so movement becomes harder over time. Flare-ups can be set off by injuries, falls, viral illnesses, or injections.

FOP is extremely rare. Cleveland Clinic estimates it affects about 1 in 2 million people worldwide. For a rough comparison, the American Cancer Society expects about 5,660 U.S. teens ages 15 to 19 to be diagnosed with cancer in 2026 alone. Because so few doctors ever see FOP, it can be mistaken for cancer or other conditions. UCSF says experts believe 80% or more of cases are misdiagnosed.

This is why LaPrade’s story matters beyond one family. When a condition is that rare, a wrong guess is easy to make. In FOP, a wrong guess can also cause harm, because some of the tests used to look for cancer can trigger new bone growth. Her path from a cancer scare to the right answer shows what is at stake when doctors have never seen the condition before.

Some Tests Used to Look for Cancer Can Cause Harm in People With FOP

LaPrade’s tests were tough for another reason. A biopsy, a spinal tap, and a catheter placed for chemotherapy can each be very painful and traumatic for someone with FOP. Doctors did not know she had it. They were following the usual path for a possible cancer. LaPrade says her road to a diagnosis was especially hard because the very tests meant to help carried extra risk for her.

That is why her community works so hard on awareness. LaPrade says this kind of trauma must be “avoided at all costs” in FOP patients. She also shares a simple clue: most people with FOP have a malformed or missing big toe, so the condition can often be suspected by looking at the toes. Medical references also list malformed big toes as a hallmark sign. For doctors, it can be a quick signal to pause.

When LaPrade was diagnosed nearly three decades ago, no treatment existed. She calls herself very optimistic, but says she never let herself hope for a treatment or cure in her lifetime. At 16, she mostly wanted her normal life back. She had a babysitting job that night and did not want a diagnosis to get in the way. Decades later, the options look very different.

Three FDA-Approved Treatments Now Exist for FOP. They Reduce New Bone Growth, but They Are Not a Cure.

Treatment has changed since LaPrade was a teenager. The FDA approved palovarotene (Sohonos) in 2023, and it has also approved garetosmab (Pasatru). On Sept. 25, 2026, it approved a third, zilurgisertib (Atebrioz), a once-daily pill for people 12 and older. That is a big shift for a disease with no approved treatment for most of her life. These drugs are designed to reduce new bone growth, and none of the approvals describes a cure.

Zilurgisertib was tested in a trial of 63 patients. After 24 weeks, the group taking it had a small drop in new bone volume, while the placebo group had a clear increase, according to reporting on the approval. Common side effects include headaches, joint pain, nosebleeds, and nausea. The label also carries a pregnancy warning. LaPrade says “there is so much hope” in her community, and that the next generation may live very differently.

The word that scared LaPrade at 16 was cancer. The word that mattered most was rare. Rare meant late answers, risky tests, and years without treatment. It also meant a community she now calls close and lifelong. Today, at 45, she works, drives, travels, and goes to concerts, even as FOP has grown more complicated with age. Her advice is simple: “take one day at a time.” For FOP, rare no longer means no options.

This article is general information, not medical advice.