On OSTEOPETROSIS - Research Paper Example

Osteopetrosis Introduction Osteopetrosis is a clinical syndrome that is characterized by failure of the osteoclasts of the bones to resorb bone tissue, resulting in failure of bone modeling and remodeling. This ultimately leads to skeletal fragility, hematopoietic insufficiency, disruption of tooth, entrapment of nerves and impairment of growth (Bhargava, and Griffing, 2009). In human, osteopetrosis is a heterogenous disorder that encompasses of different molecular lesions and a wide range of clinical features.

There are no proper epidemiologic data pertaining to osteopetrosis. The overall incidence of this condition is estimated to be 1 case in 100,000-500,000 population (Bhargava, and Griffing, 2009). Mortality associated with infantile osteopetrosis is high. Those with adult osteopetrosis have longterm survival chances. In this research essay, the pathophysiology, clinical presentation, investigations, treatment and prevention will be discussed. Purpose The main purpose of the paper is to present an overview of osteopetrosis.

Pathophysiology The main defect in osteopetrosis is in osteoclast which belongs to monocyte-macrophage lineage and genetic defects leads to abnormal osteoclasts (Tolar et al, 2004). Osteoclasts are very important in the modelling and remodeling of the tissue of the bone and defective osteoclasts fail to model and remodel the bone appropriately, resulting in abnormal encroachment and deposition of bone tissue (Teitelbaum, 2000). The abnormal bone tissue is susceptible to fractures and can encroach into the bone marrow leading to bone marrow failure.

it can also encroach around the nerves causing nerve entrapment syndrome. When blood vessels are affected, ischemia, especially of the bones like mandible can occur. Eventually, the patient develops multiple fractures, anemia, bleeding disorders and sepsis (Bhargava, and Griffing, 2009). Clinical presentation The clinical presentation depends on the type of osteopetrosis. In infantile osteopetrosis, which is also known as malignant osteopetrosis, the patient presents with growth retardation and failure to thrive (Tolar et al, 2004).

Bony defects like nasal stuffiness and sinus malformation can occur. Frequent fractures are common. Other symptoms are related to nerve entrapments, ischemia of arteries and bone marrow failure. Due to extramedullar hematopoiesis, the patient can have hepatosplenomegaly, hemolysis and hypersplenism. Sleep apnea and blindness is also common (Bhargava, and Griffing, 2009). In adult onset osteopetrosis, also known as benign osteopetrosis, there are basically 3 types which manifest as sclerosis of vault and spine, endobones of the pelvis, multiple fractires and abnormal levels of serum acid phosphatase.

Bone pains are common. Many patients develop osteomyelitis of mandible. Other manifestations include psychomotor retardaton and visual impairmen (el-Tawil and Stokert, 1993). Physical findings suggestive of osteopetrosis are short stature, large head, frontal bossing, hepatosplenomegaly, nystagmus and genuvalgum (Tolar et al, 2004). Investigations Investigations which may help in the diagnosis and monitoring the progress of the disease include serum calcium, parathormone, acid phosphatase and cratinine kinanse.

Imaging studies help in the diagnosis and evaluating the extent of the disease. Treatment The main treatments that can be offered for infantile osteopetrosis are vitamin D supplementation, gamma interferon, erythropoietin and corticosteroids. Vitamin D supplementation helps in stimulation of dormant osteoclasts. Gamma interferon helps in improving WBC function. Erythropoeitin corrrects anemia and corticosteroids help in stimulation of resorption of bone and treatment of anemia. Bone marrow transplantation helps in some infants and is the only curative treatment for this condition.

Surgical procedures may be necessary for fractures and entrapment syndromes. Nutritional support and calcium deficient diet has been found to be useful in some children. Activities of the child must be monitored to prevent fractures. In adult osteopetrosis, there appears to be no specific treatment except when complications arise (Bhargava, and Griffing, 2009). Prevention The main prevention is genetic counseling and proper family planning (Bhargava, and Griffing, 2009). Conclusion Thus, osteopetrosis is a diseases of defective osteoclasts leading to abnormal bone modeling and remodelling.

The infant form of the disease has several complications and often has poor prognosis. However, adult -onset of the disease can have good prognosis when appropriate supportive treatment is provided. The main prevention is genetic counseling and proper family planning. The curative treatment is bone marrow transplantation. References Bhargava, A., and Griffing, G.T. (2009). Osteopetrosis. Medscape. Retrieved on 18th April, 2011 from http://emedicine.medscape.com/article/123968-treatment#a1131 Tolar, J.

, Teitelbaum, S.L., Orchard, P.J. (2004). Osteopetrosis. N Engl J Med., 351(27), 2839-49. Teitelbaum, S.L. (2000). Bone resorption by osteoclasts. Science., 289(5484), 1504-8. el-Tawil, T., Stoker, D.J. (1993). Benign osteopetrosis: a review of 42 cases showing two different patterns. Skeletal Radiol., 22(8), 587-93.