Genetics

Question 1

What can tuberous sclerosis present as?

Answer 1

Infantile seizures

Question 2

Earliest cutaneous sign of tuberous sclerosis

Answer 2

Ash-leaf molecule (depigmented macules)

Question 3

Tuberous sclerosis is autosomal dominant/recessive

Answer 3

Autosomal dominant but new mutations are common

Question 4

Tumours of tuberous sclerosis

Answer 4

Periungal fibromas - around nails
Facial angiofibromas
Cortical tubers and/or calcification of the flax cerebri
Hamartomas
Angiomyolipomas
Bone cysts

Question 5

Skin signs of tuberous sclerosis

Answer 5

Ash-leaf molecule
Shagreen patches
Enamel pitting

Question 6

What are shagreen patches?

Answer 6

Fibrous hamartomas in the skin

Question 7

Hamartoma

Answer 7

Overgrowth of normal tissue

Question 8

Where is the mutation in tuberous sclerosis?

Answer 8

TSC1 or TSC2 which code for tuberin and hamartin

Question 9

What is epidermolysis bullosa?

Answer 9

A group of genetic skin fragility conditions

Question 10

3 main types of epidermolysis bullosa

Answer 10

Simplex
Junctional
Dystrophic

Question 11

Which part of the skin does simplex epidermolysis bullosa affect?

Answer 11

The dermis

Question 12

Which part of the skin does junctional epidermolysis bullosa affect?

Answer 12

Dermo-epidermal junction

Question 13

Which part of the skin does dystrophic junctional epidermolysis bullosa affect?

Answer 13

The dermis

Question 14

What is haploinsufficiency disease mechanism?

Answer 14

Only one copy of the gene is working leading to decreased protein production

Question 15

What does dominant negative mean?

Answer 15

The expression of abnormal protein interferes with normal protein

Question 16

What does gain of function mean?

Answer 16

Mutant protein gains a new function, affecting all cell processes

Question 17

What is complete loss of protein?

Answer 17

Autosomal recessive where 2 faulty copies of the gene produce no protein

Question 18

How many cafe au lait macules suggest genetic disease?

Answer 18

> 5

Question 19

Clinical features of neurofibromatosis type I

Answer 19

Cafe au lait macules and neurofibromas
Axillary or inguinal freckling
Optic glioma
Plexiform neuroma
2 or more Lisch nodules
Distinctive bony lesion

Question 20

What are cafe au lait macules?

Answer 20

Birthmarks