Christopher Santizo of Jim Thorpe was an active, healthy young man of 25 when his encounter in January with a rare blood disease called TTP left him comatose for 26 days. Santizo will likely never regain his former stamina, coordination and abilities.

TTP Thrombotic thrombocytopenic purpura causes blood clots to form in small blood vessels around the body. Platelets, blood cell fragments, help blood to clot. So when they cluster around the clots in the small vessels, too few of them are left in the bloodstream, leaving the person liable to excess bleeding, either under the skin or from cuts.

It can also cause internal bleeding, and sudden clots to develop in the brain, causing strokes, and kidneys. TTP also can cause red blood cells to break apart faster than the body can replace them. This leads to hemolytic anemia, according to the National Institutes of Health.

People can develop TTP when their bodies don't produce enough of a certain enzyme. The condition can also be inherited, and sometimes the symptoms don't appear until the person is an adult.