Genetics 1 + 2 - Science and Clinical Aspects of Genetic Skin Conditions

Question 1

Fibroma?

Answer 1

Benign tumours composed of fibrous or connective tissue

Question 2

Angiofibroma?

Answer 2

Fibromas that consist of many, often dilated, vessels

Question 3

Adenoma?

Answer 3

Benign tumour of epithelial tissue with glandular origin

Question 4

Hamartoma?

Answer 4

Overgrowth of normal tissue (totally healthy tissue growing in a disorganised fashion)

Question 5

Angiomyolipoma?

Answer 5

Benign tumour composed of blood vessels, smooth muscle cells and fat cells

Question 6

De novo mutation?

Answer 6

Alteration in a gene that is present for the fist time in one family member as a result of a mutation in a germ cell or the fertilised egg itself

Question 7

Penetrance?

Answer 7

Proportion of individuals with the mutation who exhibit clinical symptoms

Question 8

Expressivity?

Answer 8

How does a disease (or trait) show up

Question 9

Heterogenecity?

Answer 9

A phenomenon in which a single phenotype/ genetic disorder may be caused by any one of a multiple number of gene mutations

Question 10

Haploinsufficiency?

Answer 10

Phenomenon where a diploid organism has only a single functional copy of a gene (other gene mutated) and the single functional copy does not produce enough gene-product to bring about a wild-type condition, leading to an abnormal/ diseased state (caused by reduced protein production)

Question 11

Dominant negative effect?

Answer 11

Expression of abnormal protein interferes with normal protein

Question 12

Neurofibroma?

Answer 12

Benign nerve sheath tumour in the PNS

Question 13

What are the 4 ways in which mutations in genes can affect a protein and therefore cause disease?

Answer 13

Haploinsufficiency
Dominant negative effect
Gain of function
Complete loss of protein