What is Osteopetrosis?

Osteopetrosis
Features of bone from a biopsy of the iliac crestA. Severe osteopetrosis with minimal remodeling including some vascular spaces. Although the subject survived for 28 years prior to transplant, the major part of the bone was retained cartilage (lightly stained acellular material) with the balance mainly composed of primary spongiosa, and a few spaces. Low power (10× objective); the field shown is 800 µm across.B. Osteoclasts with shallow resorptive pits. Osteoclasts were present and appeared normal by light microscopy, although pits were small and shallow relative to the number of multinucleated cells present. High power (40× objective); the field shown is 110 µm across. Osteopetrosis with micro-lacunar resorption because of defective integrin organization. Blair HC, Yaroslavskiy BB, Robinson LJ, Mapara MY, Pangrazio A, Guo L, Chen K, Vezzoni P, Tolar J, Orchard PJ - Laboratory investigation; a journal of technical methods and pathology (2009). Not Altered. CC.

Osteopetrosis is a rare, hereditary, diffuse, and symmetric skeletal sclerosis caused by osteoclast dysfunction. 

What is the Pathology of Osteopetrosis?

The pathology of osteopetrosis is:

-Etiology: The cause of osteopetrosis is osteoclastic dysfunction resulting from gene mutations in at least 8 different genes.

-Genes involved: TCIRG1, CLCN7, OSTM1, PLEKHM1, SNX10, TNFSF11 and TNFRSF11A.

-Pathogenesis: The sequence of events that lead to osteopetrosis is osteoclast dysfunction. 

-Histology: The histology associated with osteopetrosis shows primarily woven bone, central core of cartilage with dense and irregular bony trabeculae, often abundant osteoclasts, and reduced marrow space.

How does Osteopetrosis Present?

Patients with osteopetrosis typically affect both males and females presenting at infancy or adulthood. The symptoms, features, and clinical findings associated with osteopetrosis include brittle bone, bone sclerosis, bone marrow failure, and extramedullary hematopoiesis.

How is Osteopetrosis Diagnosed?

Osteopetrosis is diagnosed by a thorough clinical evaluation, detailed patient history, and an X-ray. 

How is Osteopetrosis Treated?

Osteopetrosis is treated by bone marrow transplantation.

What is the Prognosis of Osteopetrosis?

The prognosis of osteopetrosis is poor with shortened life expectancy.