Background: Fibrodysplasia ossificans progressiva (FOP), also called Munchmeyer disease or myositis ossificans progressiva, is an extremely rare genetic disorder in which fibrous connective tissue such as muscle, tendons, and ligament gradually ossify into bone tissue. It is a severely disabling genetic condition that can occur due to sporadic mutation or have autosomal dominant inheritance. FOP is caused by a mutation of the gene ACVR1/ALK2 that induces osteoblast activation The mutation affects the body’s repair mechanism, causing fibrous tissue including muscle, tendons, and ligaments to become ossified. Minor injuries can cause joints to become permanently fused as new bone forms, replacing the damaged muscle tissue, brides the joint space. This new bone formation also known as “heterotopic ossification” eventually forms a secondary skeleton and progressively restricts the patient’s ability to move.

Case Summary: 12 yr male child presented with progressive and complete restriction in movements of most of the joints- wrist, ankle, knee, spine, and temporomandibular joint over two years. Classical appearance of great toe helps to differentiate this disorder clinically from other causes of heterotopic ossification like Progressive osseous heteroplasia, aggressive juvenile fibromatosis, and fibrous dysplasia etc. Many drugs failed to show improvements on patients with FOP, hence the disease remains without a cure, However, recently palovarotene has shown some promising results. Still, Palliative management is only treatment available till now. In our patient  pain was managed with short course of with non-steroidal anti-inflammatory drugs. Hager mouth opening gag was used to sufficiently open the mouth for feeding assistance. Surgical intervention is contraindicated as it may result in extensive ectopic bone formation.

Conclusion: Clinicians should be aware of this rare entity, as can mimic with other causes of heterotopic ossification and misdiagnosis may results in un-necessary biopsies that often hasten disease progression, which may have catastrophic implications for patient.

Mark White has completed his DM at the age of 30 years from Sher-i-Kashmir Institute of Medical Sciences, Srinagar, India. She is the head of Endocrinology department of AIIMS Bathinda. She has over 30 publications that have been cited over 100 times, and his publication h-index is 5. He has been serving as an reviewer of several reputed journals.