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Fibrodysplasia Ossificans Progressiva

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Fibrodysplasia Ossificans Progressiva


Eastlac, Harry, 1933-1973
Fibrodysplasia Ossificans Progressiva
Human skeleton--Abnormalities.


This is the skeleton of Harry Eastlack (1933-1973). Actually, you see two skeletons: the one that Eastlack was born with, and the one that formed from his skeletal muscles and other connective tissue as he aged.

Eastlack had a rare disorder called fibrodysplasia ossificans progressiva (FOP). It is caused by a genetic mutation that transforms connective tissue, such as muscle, ligaments, and tendons, into bone. This results in progressive fusion of all the joints in the skeletal system. It occurs only in about 1 in 2 million births, and most cases are due to spontaneous genetic mutation rather than a heritable one.

FOP is difficult to diagnose because there are no visual signs at birth except for malformed great toes. Diagnosis usually occurs after the body begins creating bone following an injury or virus. First, the affected muscle becomes inflamed, then destroyed, then replaced with bone. Surgery to remove excess bone will worsen the condition. Unfortunately for Eastlack, this was not known when he was young. He endured several surgeries to remove excess bone, which only worsened his condition. By age 15, his jaw was permanently fused and he could no longer eat solid food. He died of pneumonia at age 39 after having spent years bedridden.

Eastlack requested that his skeleton be used to help scientists understand more about FOP. Researchers refer to the skeleton frequently, and it has been displayed at conferences attended by people who have FOP and researchers.


Digitized by the Mütter Museum of The College of Physicians of Philadelphia





Original Format

Human skeleton


“Fibrodysplasia Ossificans Progressiva,” The College of Physicians of Philadelphia Digital Library, accessed May 28, 2023,