INFANTILE OSTEOPETROSIS

SYMPTOMS

The symptoms of infantile osteopetrosis can vary widely in severity and presentation but may include:

• Failure to Thrive: Infants with osteopetrosis may exhibit poor weight gain and failure to thrive due to metabolic disturbances and impaired nutrient absorption.
• Skeletal Abnormalities: Common skeletal abnormalities associated with infantile osteopetrosis include thickened bones, decreased bone marrow space, growth retardation, short stature, and limb deformities.
• Anemia: Bone marrow suppression and reduced marrow space can lead to anemia, resulting in fatigue, pallor, and susceptibility to infections.
• Craniofacial Abnormalities: Enlargement of the skull (macrocephaly), frontal bossing, hydrocephalus, cranial nerve compression, and dental abnormalities may occur due to thickening of cranial bones.
• Neurological Complications: Compression of cranial nerves, spinal cord compression, and increased intracranial pressure may result in neurological deficits, developmental delays, or sensorineural hearing loss.
• Hepatosplenomegaly: Enlargement of the liver and spleen (hepatosplenomegaly) may occur due to extramedullary hematopoiesis and storage of blood cells in the reticuloendothelial system.

DIAGNOSIS

Diagnosing infantile osteopetrosis involves a combination of clinical evaluation, imaging studies, and genetic testing. Diagnostic steps may include:

• Clinical Evaluation: A thorough physical examination is performed to assess for signs of skeletal abnormalities, growth retardation, craniofacial abnormalities, hepatosplenomegaly, and neurological deficits.
• Imaging Studies: Radiographic imaging techniques such as X-rays, computed tomography (CT), or magnetic resonance imaging (MRI) are used to evaluate bone density, skeletal abnormalities, and complications such as cranial nerve compression or spinal cord compression.
• Bone Marrow Biopsy: Bone marrow examination may be performed to assess bone marrow cellularity, hematopoietic activity, and the presence of osteoclasts.
• Genetic Testing: Molecular genetic testing can identify mutations in genes associated with infantile osteopetrosis, confirming the diagnosis and providing information about inheritance patterns.

TREATMENT

Treatment of infantile osteopetrosis aims to manage symptoms, prevent complications, and improve quality of life. Treatment options may include:

• Supportive Care: Supportive measures such as nutritional support, management of anemia with blood transfusions or erythropoietin therapy, and treatment of infections are essential for optimizing patient outcomes.
• Hematopoietic Stem Cell Transplantation (HSCT): Allogeneic hematopoietic stem cell transplantation, also known as bone marrow transplantation, is the only curative treatment for infantile osteopetrosis. HSCT can restore normal osteoclast function and halt disease progression, particularly if performed early in the course of the disease.
• Surgical Intervention: Surgical procedures may be indicated to address complications such as cranial nerve compression, spinal cord compression, or corrective osteotomies for limb deformities.
• Medical Therapy: Pharmacological interventions such as calcitriol (active vitamin D), bisphosphonates, or granulocyte-macrophage colony-stimulating factor (GM-CSF) may be used to improve bone metabolism, reduce bone turnover, and alleviate symptoms.