CHEARS

The recent news that covered almost everyone's attention and made them astounded was the 5-month-old baby girl "turning into a stone". Yes, you read it right a living human being is turning into a stone. This extremely rare genetic condition is termed as FIBRODYSPLASIA OSSIFICANS PROGRESSIVA (FOP). This is a disorder in which muscle tissue and connective tissue such as tendons and ligaments are ossified gradually. They form bone outside the skeleton that constrains movement. The estimated rate of this case is 1 in 2 million. FOP was first identified in the 18th century and there are approximately 800 known patients worldwide. It is usually seen in early children and have malformed big toes that are congenital.

What causes FOP?
Fibrodysplasia ossificans progressiva is inherited in an autosomal dominant pattern. Most cases of FOP result from new mutations in the gene. Mutations in the ACVR1 gene cause FOP. This gene provides instructions for making a member of a protein family called bone morphogenetic protein (BMP) type I receptors. The ACVR1 protein is found in many tissues of the body including skeletal muscle and cartilage. It helps to control the growth and development of the bones and muscles, including the gradual replacement of cartilage by bone that occurs in normal skeletal maturation from birth to young adulthood.

What are the signs and symptoms?
Children born with FOP often have malformed big toes, sometimes missing joint. The first flare-up that leads to the formation of FOP bone usually occurs before the age of 10. The formation of extra-skeletal bone causes progressive loss of mobility as the joints become affected. Gradually speaking and eating becomes difficult as the mouth gets affected and over a time the patient may become malnourished because of the inability to eat. They may also develop breathing difficulties as a result of extra bone formation around the rib cage that restricts expansion of the lungs. Any trauma to the person with FOP(a fall) may trigger episodes of muscle swelling and inflammation followed by more rapid ossification in the injured area. Ossification is typically first seen in the dorsal, axial, cranial and proximal regions of the body. However,it does not necessarily occur in this order due to injury-caused flare-ups. Individuals get bedridden by the age of 20 and manage to survive till the age of 40 if proper medical management is followed.

How is it diagnosed?
Diagnosing FOP is challenging as it is very rare and, most of the time it maybe misdiagnosed. Outbreaks maybe measurable clinically by elevated levels of alkaline phosphatase and bone-specific alkaline phosphatase. The Genetic Testing Registry(GTR) provides information about the genetic tests for this condition.

How is it treated?
FOP has no permanent treatment as of now. Biopsies, intramuscular injections,falls, stretching of jaws in dental therapy must be avoided as they may result in rapid bone formation in those areas. High dose of corticosteroids, such as Prednisone, started within the first 24 hours of a flare-up may reduce the intense inflammation and tissue swelling in early stages. Other medications, such as muscle relaxants, mast cell inhibitors, and aminobisphosphonates can be used under close monitoring of a physician. Surgery is very risky and can cause painful new bone growth. Affected individuals may contact occupation therapist who can help obtain special devices or tools to assist them in daily activities. Special shoes,braces, and other devices that assist in walking and weight-bearing have been useful. Genetic counseling may be of benefit for families with inheritance of FOP.