What is TIO?
TIO is a rare disease caused by slow-growing tumors that occur throughout the body.
The tumors responsible for tumor-induced osteomalacia (TIO) can often be removed with surgery, which can lead to the levels of phosphorus in the body returning to normal. Sometimes, the tumors are too small to find or are in a location where they can't be removed.
Osteomalacia, or “soft bones,” is a weakening of the bones due to low levels of vitamins and minerals, including phosphorus, calcium, and vitamin D. Phosphorus is a mineral that is important for bone health.
If the tumors cannot be located or removed, the symptoms of TIO can get worse over time.
In a clinical review of 895 unique cases of TIO, the majority of cases occurred in adults between 30 and 60 years of age, although TIO can occur at any age.
What causes TIO?
The underlying cause of hypophosphatemia in TIO is too much FGF23:
Tumors in the body produce too much of a hormone called fibroblast growth factor 23 (FGF23)
Extra FGF23 leads to the body releasing too much phosphorus through the urine
Low phosphorus levels can lead to weakened bones and the symptoms of TIO
In people with TIO, the most common locations for fractures are:
Vertebrae
Ribs
Femur
Pelvis
More is known about TIO than ever before, including how to treat it. Ask your doctor if CRYSVITA could be right for you.
