MSK

Question 1

What happens in a PHEX loss of function mutation?

Answer 1

• osteomalacia
• low serum phosphate
• high urine phosphate
• High FGF-23
• X-linked hypophosphataemic rickets

Question 2

what occurs in the bone remodelling process?

Answer 2

1. The bone remodelling process begins when the cells lining the bone surface are activated to form osteoclasts.
2. Osteoclasts secrete acid, which dissolves the bone mineral, to form resorption cavities (pits).
3. Osteoblasts are recruited to the resorbed bone and secrete osteoid matrix, which is comprised mainly of collagen.
4. Over time, the osteoid matrix becomes mineralized to form bone