the disease that turns muscles into “stone”

A 12-year-old girl shows up at a hospital in India with her parents. Her backback is distorted by several massesmasses hard and painful symptoms that appeared after falling out of bed six months earlier. The doctors are worried because these do not seem to be of inflammatory origin and, apart from these bumps, the young patient is in apparent good health. However, a small detail will lead them on the trail of a strange and extremely rare disease: progressive ossificans fibrodysplasiaprogressive ossificans fibrodysplasia.

When bones grow all over the body

The bumps growing on the girl’s back are not swelling, cystscysts or a cancerous mass, these are bones. New bones growing in place of his muscles and tendons. Spontaneously or after trauma, even minimal, fibrodysplasia ossificans progressiva transforms the tissues fibrousfibrous in stone. » Generally diagnosed in the first two decades of life, this disease only affects one in a million people. The first sign of the disease, which often goes unnoticed, is a malformationmalformation big toes; sometimes, a simple Hallux valgus to more serious atrophy.

Fibrodysplasia ossificans progressiva is caused by a mutation geneticgenetic autosomal in the embarrassedembarrassed ACVR1 directly involved in bone development and repair. Except that in the presence of a mutation, its action is deregulated. When fibrous tissues (smooth muscles and heart muscleheart muscle are not affected) experience shock, stem cells activate to repair the damaged area, but in people with the ACVR1 mutation, the stem cells turn into bone cells. Muscles, tendons and ligaments ossify over time, restricting the movementsmovements patients until the intercostal muscles are affected in turn and prevent breathing.

L’life expectancylife expectancy with fibrodysplasia ossificans progressiva is 56 years on average. Treatments exist to relieve symptomssymptoms but none can stop the creation of new bone tissue.