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Paediatrics
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Osteopetrosis - Marble Bone Disease

Metabolic Bone Disease

A 4-month-old infant presents with failure to thrive, hepatosplenomegaly, and anaemia requiring transfusion. The parents report the child has not been fixing or following objects. Examination reveals nystagmus and pale optic discs. Plain radiographs show uniformly dense bones throughout the skeleton with loss of the medullary cavity. Haemoglobin is 65 g/L with nucleated red blood cells on smear. Regarding this condition:

Mark each as TRUE or FALSE

A

Osteopetrosis results from defective osteoclast function leading to failure of bone resorption; the ...

B

Optic nerve compression through narrowed optic canals causes progressive blindness in 80% of infanti...

C

Despite increased bone density, fractures are rare due to the thickened cortices; bone marrow failur...

D

Fractures occur paradoxically despite dense bone because the bone lacks normal lamellar structure an...

E

Specific genetic mutations determine phenotype: TCIRG1 mutations cause 50% of ARO cases; CLCN7 mutat...

Answer the questions to see explanations

Click T (True) or F (False) for each option