Fibrodysplasia Ossificans Progressiva rare disorder

Fibrodysplasia Ossificans Progressiva is an extremely rare connective tissue disorder.This disorder occurs rare which is believed in approximately 1 in 2 million people worldwide.Before going deep into this, lets know some basic to this diorder.

Damaged tissue healed with the Bone (credit)

Connective tissues are those tissue that mainly connects, seperates, supports other tissues or organs.Fibrous tissues are those composed mainly with bundles of collagen white fibers lying between the rows of connective tissuse (Eg: Muscle tendon ligament). So this disease is mainly concerned with the mutation occurring in the body's repair mechanism which give rise to the fibrous tissue to be replaced by bone (ossified) damage or spontaneously.This condition forms the bone outside the skeletal system (extra-skeletal or heterotropic bone) that blocks and freezes the movenment. So this condition is also termed as "Stone Man Syndrome"

According to the genetic information , there is the mutation in the ACVR1 gene which causes this Fibrodysplasia Ossificans Progressiva. On the basis of study of this gene, this ACVR1 gene mainly provides the instructions for producing the member of protein family which is called as Bone Morphogenetic Protein (BMP) type I receotor. This protein is found in many tissue of the human body including the skeletal muscles and the cartilages. This protein functions occurring in normal skeletal maturation from birth to the young adulthoods acts mainly to control the development of the muscles and the bones which includes the gradual replacement of the cartilages by bone which is termed as ossification.

Mutation in the ACVR1 gene (credit) - cytogenetic location:2q24.1 in the long arm of chromosome 2 at position of 24.1

Many researchers have believed in the study that this mutation in the ACVR1 gene might change or modify the shape of the receptor under certain pathological conditions and may disrupt mechanisms that might control the receptor's activity. Due to this, there is the constant turning on of the receptor which is called as a Constitutive activation. This action in the receptors cause the overgrowth of the bone and the cartilages and also fusion of the joint which therby results into the sign and symptoms of the condition Fibrodysplasia Ossificans Progressivva.

If a person falls or any trauma to the muscle of individual with this condition, or any invasive medical procedures, this all may trigger the episodes of swelling of muscels and various types of inflammation termed as "Myositis" followed by more and more rapid ossification in the area of injury .Flare-ups occurs during the viral illness like influenza condition .

Connective soft tissue turning into bone

(credit)

Generally, with Fibrodysplasia Ossificans Progressiva , new borns have presentation of malformed big toes. And this presentation is the main characteristic feature which also helps to distinguish this disorder from the other common problems related to the muscles and bones .So, the affected individual tent to have short thumbs and other skeletal and bone abnormalities.

This condition is mainly inherited in an autosomal dominant pattern which generally means any one of the copy of gene in each cell is enough for the cause of this disorder.This disorder mainly occurs in the whites, but it is also reported in the blacks .

So what are the changes that we can see in this person suffering from Fibrodysplasia Ossificans Progressive ?

Abnormality of toe (credit)

A progressive bone formation takes place in the areas of the body where bone is not present normally which is termed as heterotopic Ossification which occurs normally during the early childhood stage. This can occur during the stages of adolescents or say early adolescent and even throughout the life. Soft tissue injury or a viral illness is followed in this disorder with rapid abnormal development of the bone. For the heterotopic Ossification, the foremost symptoms is the swelling of the firm tender appears in the parts of shoulder, head and neck. This bony growth include the tendons,skeletal muscels tissue,connective tissue and even the ligaments including the fascia and aponeuroses covering it . There is the stiffness and cases of pain in the areas.Even when the swelling subsides, there is the hardening of the bone while decreasing in the size

The bone slowly replaces the connective tissues and skeletal muscle fibers. The bone grows even in various tendons, ligaments and bands of fibrous tissue supporting the muscle fibers. Usually, the first affected area is the neck, back, chest , shoulder, arms and legs. As this progresses, it starts affecting the hips, ankles, wrists, elbows , jaws and addition with abdominal wall.

Individual slowly imprisoned by a second skeleton (credit)

On the Diagnosis ?

Since this disorder is very rare, it is oftenly misdiagnosed as the cancer or fibrosis. Biopsies are done by the physician which can verify the growth of the lumps. As the child grows with the big toe, it is confirmed in the early age. Clinically, it is measurable in terms of levels of alkaline phosphatase and bone-specific alkaline phosphatase. Genetic testing is done for the disorder with the 24 available tests .

For the Cure ,

Systematic steroids are used in the flare-ups. Using the iontophoresis along with steroids or acetic acid improves diminished range of motion. Therapies related based on blocking the activinlike kinase-2 or blocking the activin receptor IA/activin-like kinase 2 signaling are used.

As the medication are less, the surgical procedure are commonly practised . Oral surgical and anesthetic procedures are used in controlling oral pain.