Collagen and connective tissue diseases

Question 1

What is collagen V essential for?

Answer 1

Type I collagen fibril formation

Question 2

Describe collagen V

Answer 2

N terminus pertrudes from fibril
Template for developing fibril
Regulates lateral expansion
Type XI collagen has similar role in type II collagen fibril

Question 3

FACIT

Answer 3

Fibril Associated Collagen with Interrupted Triple Helix
on surface of collagen fibrils
Interact with other fibrils and matrix molecules

Question 4

Osteogenesis Imperfecta

Answer 4

Blue sclarae, hearing loss, weak tendons, thin skin
Severe forms lethal in utero, mild forms have few fractures
Type I to IV all caused by dominant mutations in COL1A1 or COL1A2

Question 5

What is Mild OI (type I) ?

Answer 5

Reduced amounts of normal type 1 collagen (Haploinsufficiency of COL1A1)
Frame-shift and ne termination point
Less normal type 1 collagen

Question 6

What is lethal OI type II?

Answer 6

Single point mutation
G to T mutation
Abnormal collagen - alterred mobility of COL 1 alpha chains
disulphide bond between adjacent alpha 1 chains
Collagen has reduced thermal stability

Question 7

What is severe deforming OI type II?

Answer 7

Lycine mutation

Question 8

How is the position of Gly > Cys mutation associated with severity?

Answer 8

Closer to C - terminus the more severe

Triple helix formation begins at C terminus