Fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva (FOP) is an extremely rare disease of the connective tissue. A mutation of the body's repair mechanism causes fibrous tissue (including muscle, tendon, and ligament) to be ossified when damaged. In many cases, injuries can cause joints to become permanently frozen in place. Surgical removal of the extra bone growths has been shown to cause the body to "repair" the affected area with more bone.

The best known FOP case is that of Harry Eastlack (1933–1973). His condition began to develop at the age of ten and, by the time of his death from pneumonia in November 1973, six days before his 40th birthday, his body had completely ossified, leaving him able to move only his lips.

Shortly before Eastlack's death he made it known that he wanted to donate his body to science, in the hope that in death he would be able to help find a cure for this little-understood and particularly cruel disease. Pursuant to his wishes, his preserved skeleton is now kept at the Mütter Museum in Philadelphia, and has proven to be an invaluable source of information in the study of FOP.