Rare disease - causing patients to turn to stone

[postlink]http://med-mysteries.blogspot.com/2010/05/rare-disease-causing-patients-to-turn.html[/postlink]http://www.youtube.com/watch?v=FsFPt0FATJcendofvid [starttext]the story of patients who have disease causing their soft tissue - muscle, ligaments, tendons - to turn to literal stone. It's like their skeleton is forming a skeleton, which will eventually immobilize them. [endtext]