Genetics

Question 1

What is Tuberose Sclerosis

Answer 1

Multi-gene disorder
Autosomal dominant condition
2nd most common genodermatose

Question 2

How does Tuberose Sclerosis present?

Answer 2

Ash leaf (depigmented) macule
Infantile seizures

Question 3

Name 4 tumours associated with Tuberose Sclerosis

Answer 3

Periungal fibromas
Facial angiofibromas
Hamartomas
Bone cysts

Question 4

Which genes are defective in Tuberose Scelorisis

Answer 4

TSC1 and TSC2
Codes for tuberin and harmatin
Substances along tumour regulating gene pathway

Question 5

Describe features of Autosomal Dominant pattern of inheritance

Answer 5

Disease seen in ALL generations
50% risk of affected parent passing gene to child
(+4 more)

Question 6

What does genetic heterogeneity mean in terms of TS?

Answer 6

Mutation may be in either TSC1 or TSC2

Question 7

What does penetrance mean in terms of TS?

Answer 7

Some people do not show features of the disease even if they have the mutation

Question 8

What is Epidermolysis Bullosa (EB)?

Answer 8

Genetic skin fragility conditions
Dominant, recessive, new mutation or acquired
Varying severity

Question 9

What are the 3 types of Epidermolysis Bullosa?

Answer 9

Simplex
Junctional
Dystrophic

Question 10

Which part of the skin does Simplex EB affect?

Answer 10

Keratinocytes in the keratin layer

Question 11

Which part of the skin does Junctional EB affect?

Answer 11

Dermo-epidermal junction

Question 12

Which part of the skin does Dystrophic EB affect?

Answer 12

Dermis

Histology similar to a burn. Constant skin healing with scarring - finger webbing

Question 13

How many genes are involved in EB?

Answer 13

10

Question 14

Describe the dominant-negative disease mechanism.

Answer 14

Mutant protien stops normal protein working.

Question 15

Describe features of Autosomal Recessive pattern of inheritance

Answer 15

Only one generation affected
25% risk of affected child if parents are carriers
Increased risk in consanguineous families

Question 16

How does neurofibromatosis type i present?

Answer 16

Cafe-au-lait macules
Neurofibromas
Axillary/inguinal freckling
Diffuse plexiform neuroma 
(+3 more)

Question 17

Which structural protein is implicated in the development of atopic dermatitis?

Answer 17

Filaggrin

Question 18

Which immunological proteins are implicated in the development of atopic dermatitis?

Answer 18

IL-4

IL-13

Question 19

Which skin condition is caused by a mutation of filaggrin genes?

Answer 19

Ichthyosis vulgaris

Question 20

What does filaggrin “stand for”?

Answer 20

FILament AGGregating proteIN

Question 21

Which atopic conditions are affected by lack of filaggrin?

Answer 21

Increases risk of:

• eczema
• asthma, hay fever
• peanut allergy