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Flashcards in Genetics Deck (23)
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1
Q

A 35yo lady presents with periungual fibromata and longitudinal ridging on hands and feet, epilepsy from 7yo and normal intelligence, diagnosis?

A

Tuberose Sclerosis

2
Q

What is the earliest cutaneous sign of Tuberose Sclerosis?

A

Ash-leaf macule

3
Q

Where will periungual fibromas be found?

A

Around nails

4
Q

What tumours may be found in Tuberose Sclerosis?

A

Periungual fibromas, facial angiofibromas, cortical tubers and/or calification of falx cerebri, hamartomas, bone cysts

5
Q

What can cortical tubers cause?

A

Epilepsy, mental impairment (to varying degrees)

6
Q

What type of genetic disorder is Tuberose Scleroris?

A

Autosomal Dominant

7
Q

The genes TSC 1/2 are involved in Tuberose Sclerosis, what do they code for?

A

Tuberin and hamartin

8
Q

What does Epidermolysis Bullosa describe?

A

A group of genetic skin fragility conditions. Dominant,recessive, new mutation or acquired with variable severity

9
Q

What are the 3 main types of Epidermolysis Bullosa?

A

Simplex, junctional and dystrophic

10
Q

How many genes are involved in Epidermolysis Bullosa?

A

10

11
Q

What overall aspects of the skin are effected by Epidermolysis Bullosa?

A

Structure and adhesion

12
Q

What does a dominant-negative disease mechanism cause in terms of protein fomation?

A

Aggregates are formed instead of filaments with the mutant gene

13
Q

What does a Haploinsufficiency (dominant) disease mechanism cause in terms of protein formation?

A

Less protein formed

14
Q

What does a Recessive disease mechanism cause in terms of protein formation?

A

No protein formed

15
Q

What does haploinsufficiency mean?

A

Only one copy of working gene- reduced protein production

16
Q

What does dominant negative mean?

A

Expression of abnormal protein interferes with normal protein

17
Q

What does gain of function mean?

A

Mutant protein gains a new function, affecting cell processes

18
Q

A 14 yo bold presents with multiple asymptomatic coffee coloured flat marks, onset last few years. Slight learning difficulties, otherwise good health. What is the clinical sign and diagnosis?

A

Cafe au lait macules: neurofibromatosis type 1

19
Q

More than how many cafe au lait macules suggests genetic disease?

A

> 5

20
Q

What 2 main clinical signs may be seen in Neurofibromatosis type 1?

A

Cafe au lait macules and neurofibromas

21
Q

What features may be seen in NF1?

A

Cafe au lait, neurofibromas, plexiform neuroma-diffuse, axillary/inguinal freckling, optic glioma, >=2 Lisch nodules, distinctive bony lesion

22
Q
A

Atopic eczema

23
Q

What do filaggrin mutations cause?

A

Ichthyosis vulgaris