QuestionSBA
QuestionChoice
Defects in type IV collagen result in Alport syndrome, which has characteristic features of renal impairment, eye changes (especially to the lens or cornea), and sensorineural hearing loss.
10027014
d
Type IV collagen
QuestionChoice
Defects in fibrillin result in Marfan syndrome, characterised by disproportionally long and slender limbs, anterior chest wall deformity, lens dislocation, heart murmurs and spontaneous pneumothoraces.
10027013
c
Fibrillin
QuestionChoice
Defects in type III collagen cause Ehlers-Danlos vascular type which is associated with features such as thin, fragile, translucent skin, short stature, fragile blood vessels that can rupture, and characteristic facial features. The features listed in the vignette are more consistent with classical Ehlers-Danlos.
10027012
b
Type III collagen
QuestionChoice
Abnormal forms, or a reduction in Von Willebrand factor result in Von Willebrand disease, the most common inherited bleeding disorder which characteristically causes bruising, epistaxis and menorrhagia. Von Willebrand's disease would not account for the joint hypermobility and skin elasticity described in the vignette.
10027015
e
Von Willebrand factor
QuestionChoice
The child in the vignette likely has Ehlers-Danlos classical type (formally called type 1), an autosomal dominant condition associated with elastic skin, bruising and joint hypermobility. This is caused by defects in type V collagen.
10027011
a
Type V collagen
Concept
Chapter
2693
5946
Ehlers Danlos syndrome
Topic
156
Medical Genetics
17800
A mother brings her 6-year-old son to the GP, concerned that he bruises very easily. Upon further discussion, his mother admits that he also has ‘stretchy skin’ and is ‘very flexible.’ The child’s father also has these features.

Given the most probable diagnosis, the child is likely to have inherited a defect in which protein?
a