Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MSK-Derm by Minnie AH Version > SM 245a - Inherited Disorders of Connective Tissue > Flashcards

SM 245a - Inherited Disorders of Connective Tissue Flashcards

You may prefer our related Brainscape-certified flashcards:
Dermatology Board Prep flashcards
1
Q

Which connective tissue abnormality?

Mutationin COL1A1 or COL1A2

A

Osteogenesis imperfecta

(Abnormal Type I Collagen, due to COL1A1 or COL1A2 mutation; Autosomal dominant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which connective tissue abnormality?

Joint hypermobility

A

Ehlers-danos syndrome

(Abnormal Type V Collagen; COL5A1 or COL5A2; Autosomal dominant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which connective tissue abnormality?

Long limbs, fingers, toes

A

Marfan Syndrome

(Abnormal Fibrillin 1 -> impaired elastin function; autosomal dominant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which connective tissue abnormality?

Mutation in COL5A1

A

Ehlers-danos syndrome

(Abnormal Type V Collagen; COL5A1 or COL5A2; Autosomal dominant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What gene mutation results in hypochondroplasia?

What is the result?

A

Mutation in FGFR3 (usually Gly380Arg)

  • -> FGFR3 receptor is constituitively activated
  • -> Constant inhibiton of chondrocyte hypertrophy
    • Results in decreased chondrocyte proliferation, and therefore decreased bone growth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the features of Ehlers-Danlos Syndrome

A
  • Soft, velvety, hyperelastic, fragile skin
    • Tears and bruises easily
    • “cigarette paper” scars
  • Molluscoid pseudotumors
  • Joint hypermobility, dislocations
  • Mitral valve prolpse
  • Hiatal hernia
  • Anal prolapse
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What causes Ehlers-Danlos syndreome?

A

Abnormal Type V Collagen due to haploinsufficiency

Due to mutations in COL5A1 or COL5A2

Autosomal dominant

(Abnormal Type V Collagen; COL5A1 or COL5A2; Autosomal dominant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the features of perinatal lethal osteogenesis imperfecta

A
  • Congenital fractures
  • Accordion-like ribs: Chest wall is unstable, cannot inflate lungs
  • Poor skull ossification “Wormian bones”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which connective tissue abnormality?

Associated with mitral valve prolapse

A

Ehlers-danos syndrome

(Abnormal Type V Collagen; COL5A1 or COL5A2; Autosomal dominant)

Marfan Syndrome

(Fibrillin 1, Autosomal dominant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the inheritance pattern of osteogenesis imperfecta?

A

Autosomal dominant

Varying forms

  • Dominant negative = very severe
  • Haploinsufficiency = mild
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the inheritance of Marfan Syndrome

A

Autosomal dominant

30% of cases are new mutations

Variable expressivity, fully penetrant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which zone is affected by achondroplasia?

A

Zone of hypertrophy – it is too small

Chondrocyte hypertrophy, and therefore proliferation, is inhibited
(Contituitive inhibition due to FGFR3 mutation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What causes osteogenesis imperfecta?

A

Abnormal Type I Collagen

Due to mutation in COL1A1 or COL1A2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which connective tissue abnormality?

Hyperelastic, fragile skin

A

Ehlers-danos syndrome

(Abnormal Type V Collagen; COL5A1 or COL5A2; Autosomal dominant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the features of osteogenesis imperfecta

A
  • Abnormal Type I collagen
  • Wide range of severity
  • Fractures with minimal trauma
    • Tend to decrease after puberty
  • Short limb dwarfism
  • Blue sclera
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which connective tissue abnormality?

Fragile bones

A

Osteogenesis imperfecta

(Abnormal Type I Collagen, due to COL1A1 or COL1A2 mutation; Autosomal dominant)

17
Q

What is the role of TGF-beta in the pathogenesis of Marfan syndrome?

A

Normally, fibrillin 1 forms a scaffold for the latent complex of TGF-beta

Abnormal fibrillin 1 (Marfan syndrome) means that the latent complex cannot bind, resulting in release of TGF-beta and excess TGF-beta signaling

  • Emphysema
  • Mitral valve prolapse
  • Aortic aneurysm
    • Also due to no fibrillin 1 scaffold for elastin
  • Myopathy
18
Q

Describe the features of Marfan syndrome

A
  • Long limbs
  • Long fingers and toes (thumb sign, wrist sign)
  • Flat feet
  • Scoliosis
  • Ectopia Lentis
    • Dislocation of the lens of the eye
  • CV effects
    • Aortic insufficiency, dilation, dissection
    • Abdominal aortic aneurysm
  • Pulmonary
    • Pneumothorax
    • Apical bleb
  • Skin and integument
    • Hernias
    • Striae distensae
  • CNS
    • Dural ectasia
    • Lumbosacra meningocele
19
Q

Describe the pathophysiology of Marfan syndrome

A

Abnormal Fibrillin 1

  • Monomers cannot associate to form connective tissue microfibrils in the inter-cellular matrix
    • They are supposed to act as scaffolds for the deposition of tropoelastin in elastic fiber formation
  • No scaffold ->
    • Elastin function is disrupted
    • Latent complex released, TGF-beta activated; excess signaling
      • Emphysema, mitral valve prolapse, aortic aneurysm, myopathy
20
Q

Which connective tissue abnormality?

Wormian bones

A

Perinatal lethal osteogenesis imperfecta

(Abnormal Type I Collagen, due to COL1A1 or COL1A2 mutation; Autosomal dominant)

21
Q

What is the potential role of NPR-B in treating achondroplasia?

A
  • CNP activates NPR-B, resulting in the inhibition of the inhibitory pathway initiated by FGF:FGFR3
  • This inhibits the inhibition of chondrocyte hypertrophy, resulting in the restored proliferation of chondrocytes
22
Q

Which connective tissue abnormality?

Blue sclera

A

Osteogenesis imperfecta

(Abnormal Type I Collagen, due to COL1A1 or COL1A2 mutation; Autosomal dominant)

23
Q

Which connective tissue abnormality?

Associated with aortic dilation, aortic regurgitation, aortic dissection, abdominal aortic aneurysm

A

Marfan Syndrome

(Abnormal Fibrillin 1 -> impaired elastin function; autosomal dominant)

24
Q

Describe the radiographic findings of achondroplasia

A
  • Roof of acetabulum is horizontal
  • Ilium is a “paddle without a handle”
  • Deep sacro-sciatic notch
25
Q

What is the inheritance pattern of achondroplasia?

A

Autosomal dominant

Most cases are due to new mutations – Affected by paternal age

26
Q

What are the characteristics of achondroplasia?

A
  • Short stature
  • Disproportionate shortening of proximal limb segments
  • Short base of skull w/large head
  • Stenosis of foramen magnum and spinal canal
  • Central and obstructive apnea
  • Normal intelligence
27
Q

Which gene is mutated in people with Achondroplasia?

How is the protein affected?

A

FGFR3 (Gly380Arg)

  • Normally, when FGF binds to its site on FGFR3, chondrocyte proliferation is inhibited
  • In achondroplasia, FGFR3 is constituitively on, resulting in constituitive inhibition of chondrocyte proliferation
28
Q

What causes Marfan Syndrome?

A

Abnormal fibrillin 1

MSK-Derm by Minnie AH Version (47 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions