Fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva
Fibrodysplasia ossificans progressiva
Specialty	Rheumatology

Fibrodysplasia ossificans progressiva (FOP), is a 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 (turned to bone) when damaged. In many cases they can cause joints to become permanently frozen in place. The growths cannot be removed with surgery because such removal causes the body to "repair" the area of surgery with more bone.

Prognosis

Over time, as more bone grows the patient increasingly loses mobility. It may become impossible for the patient to reach, walk, eat, or even breathe. The disease is fatal as bone will eventually paralyze the diaphragm. People with FOP usually lose all mobility by the age of 30 and die by the age of 40. There is no cure; however, Dr. Frederick Kaplan of the University of Pennsylvania has found a gene that is linked to FOP that could theoretically lead to one.^[1]

Symptoms

Children born with FOP characteristically have short big toes. The first "flare-up" that leads to the formation of FOP bones is usually before the age of 10. Often, the tumor-like lumps that characterize the disease appear suddenly overnight. Because the disease is so rare, the symptoms are often misdiagnosed as cancer. This leads doctors to order biopsies, which can actually exacerbate the growth of these lumps.

Cases

Since the 1800s there have been periodic references in medical literature describing people who apparently "turned to stone", and it is possible that some of these cases may have been attributable to FOP.

Perhaps the most well-known FOP case condition began to develop around the age of ten, and at the time of his death from pneumonia in November 1973 (six days before his fortieth birthday), his body had completely ossified, leaving him able to move only his lips.

What makes Mr. Eastlack’s case particularly notable is that shortly before his 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. As per his wishes, his preserved skeleton now resides in The Mütter Museum (see a QuickTime animation) in the College of Physicians of Philadelphia, and has proven to be an invaluable source of information in the study of FOP.

Treatment

Those diagnosed with FOP should try to avoid falling or getting bruises, and avoid intramuscular injections since these can cause bone to grow. Likewise, people with FOP should never stretch their joints outside of their normal range of motion. However since flare-ups can occur spontaneously, even perfect preventive care cannot guarantee the absence of bone growths.

Causes

FOP is caused by an autosomal dominant allele on chromosome 2q23-24. The allele has variable expressivity, but complete penetrance. Most cases are caused by spontaneous mutation in the gametes; most people with FOP cannot have children. About 2,500 cases have been reported to date, but a study has determined that it affects approximately 1 in 2 million people. A similar but less catastrophic disease is Fibrous dysplasia, which is caused by a post-zygotic mutation.

Researchers from the University of Pennsylvania announced in April 2006 that a mutation in the gene ACVR1 is responsible for the disease.^[2] ACVR1 encodes activin receptor type-1, a BMP type I receptor.

Fibrodysplasia ossificans progressiva in popular culture

The subject of Fibrodysplasia ossificans is discussed in a Dinosaur Comic.[1]

"Leaning Man" The Jud Bogard Story is a documentary currently in production, it deals with Jud who has FOP, and his inspirational story as a person living with the disease. Produced by Paul Sadowski & Vincent H. Ly. (2007) www.judbogard.com

A patient on Grey's Anatomy (Season 3, episode 19: "My Favorite Mistake") had this disease. She was reduced to the use of only her hands and face.

Sources

References

^ "When Body Turns to Bone". ABC News. {{cite journal}}: Cite has empty unknown parameter: |month= (help)
^ Shore, E.M.; et al. (2006). "A recurrent mutation in the BMP type I receptor ACVR1 causes inherited and sporadic fibrodysplasia ossificans progressiva". Nature Genetics. Advance online publication 23 April 2006. {{cite journal}}: Cite has empty unknown parameter: |month= (help); Explicit use of et al. in: |author= (help)

External links

[1] "When Body Turns to Bone". ABC News. {{cite journal}}: Cite has empty unknown parameter: |month= (help)

[ACVR1-2] Shore, E.M.; et al. (2006). "A recurrent mutation in the BMP type I receptor ACVR1 causes inherited and sporadic fibrodysplasia ossificans progressiva". Nature Genetics. Advance online publication 23 April 2006. {{cite journal}}: Cite has empty unknown parameter: |month= (help); Explicit use of et al. in: |author= (help)

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