Disorders of the Growth Plate

Question 1

What type of cretinism leads to defective cartilage maturation?

Answer 1

Maternal iodine deficiency

Question 2

What is Morquio syndrome?

Answer 2

A mucopolysaccharidosis that leads to mucopolysaccharide deposition in chondrocytes and severe dwarfism

Question 3

What is the name of the syndrome of short-limbed dwarfism and macrocephaly?

Answer 3

Achondroplasia

Question 4

Describe the molecular and cellular pathogenesis of achondroplasia

Answer 4

• Molecular - Activating mutation in FGFR3
• Cellular - Failure of normal epiphyseal cartialge formation

Question 5

Describe the molecular mechanism that leads to scurvy

Answer 5

1. Vit C deficiency
2. INability to hydroxylate proline and lysine
3. Unstable collagen

Question 6

What is scoliosis?

Answer 6

Lateral curvature of the spine

Question 7

What is kyphosis?

Answer 7

Anteroposterior curvature of the spine

Question 8

What is the pathologic cause of osteochondroma?

Answer 8

If the Ring of Ranvier is absent/defective, the growth plate grows laterally into the soft tissue

Question 9

Describe the molecular pathogenesis of Hereditary Multiple Osteochondromatosis

Answer 9

Austosomal Dominant disorder characterized by loss of the EXT1 or EXT2 gene function

Question 10

What is the general name for conditions in which one limb’s growth plate is stimulated to undergo rapid and prolonged endochondral ossification?

Answer 10

Hemihypertrophy