Flashcards in 20. Osteopetrosis (marble bone disease) Deck (17)
Osteopetrosis is also called
marble bone disease
osteopetrosis ( marble bone disease ) - pathophysiology
Carbonic abhydrase ---> impair ability of osteoclast to generate acidic enviroment ( necessary for bone resorption ) --> thichkened, dense bones
thichkened, dense bones of osteopetrosis prone to
osteopetrosis - clinical manidestation ( why )
1. pancytopenia ( bone fills marrow space )
2. extramedullary hematopoiesis ( bone fills marrow )
3. cranial nerve inmpingement and palsies ( narrowed foramina )
4. hydrocephalus ( narrowing of the foramen magnum )
5. bone fractures
6. renal tubular acidosis ( carbanhydr II mut )
the hole in the base of the skull through which the spinal cord passes
osteopetrosis - nerve inpingementd and palsies can cause
vision and hearing impairment
osteopetrosis - renal involvement
renal tubular acidosis ( carbanhydr II mut ) --> decreased tubular reabsorption fo HCO3- --> metabolic acidosis
osteopetrosis - X-ray - appearance
bonr - in bone appearabce
osteopetrosis - cranial nerve inmpingement and palsies due to
osteopetrosis - hydrocephalus due to
narrowing of the foramen magnum
treatment of osteopetrosis ( why)
Bone marrow transplant is potentially curative as osteoclasts derived from monocytes
• A patient has been told he has dense bones, yet he is frequently fracturing them. What might he have?
Osteopetrosis (marble bone disease)
• In osteopetrosis, bone ____ (resorption/breakdown) is impaired as a result of abnormal ____ (osteoblasts/osteoclasts).
• In osteopetrosis, serum Ca2+ is ____ (high/normal/low), PO43- is ____ (high/normal/low), alkaline phosphatase is ____ (high/normal/low).
Normal, normal, normal
• What hematologic complications may arise from osteopetrosis?
Anemia, thrombocytopenia, infection (secondary to leukopenia), increased extramedullary hematopoiesis
What neurologic lesions may result from osteopetrosis? Why?
Cranial nerve palsies due to narrowed foramina in the skull