I am a grad student in the lab that studies the genetic disease Fibrodysplasia Ossificans Progressiva (FOP). You saw the TIL, now AMA!
I'm a 5th year graduate student at the University of Pennsylvania, and I work in the lab or Dr. Eileen Shore and Dr. Fred Kaplan. Our lab, part of the McKay Orthopaedic Research group, studies FOP and another related genetic disorder, POH.
The lab has been in existence for about 20 years, and in 2006 the group published the gene (and mutation) that causes FOP - sorry, behind Nature Medicine pay wall. The mutation is a R206H missense mutation at codon 206 in the gene ACVR1, also known as ALK2. ALK2 is a BMP signaling receptor, and while BMPs have been shown to be involved in many life processes, their original discovery was as a factor that induces bone growth, not surprisingly.
There's much that has been learned about FOP since the gene/mutation discovery in 2006, but I'll let you direct the questions. AMA!