Week 1

Question 1

What is FISH

Answer 1

Technique used to locate a dna sequence on a chromosome

Used to visualise and map genes

Can identify mutations

Question 2

What is a germ line mutation

Answer 2

Inherited

Question 3

What is an acquired mutation

Answer 3

A mutation acquired after conception

Question 4

What are the two types of functional mutation

Answer 4

Favourable
Non-favourable

Question 5

What is a silent mutation

Answer 5

A mutation with no change to amino acids

Question 6

What is a missense mutation

Answer 6

A mutation that changes one amino acid

Question 7

What is a nonsense mutation

Answer 7

Change in amino acid which changes a stop codon

Question 8

What is a frame shift mutation

Answer 8

Disruption of the triplet code
Can be insertion or deletion

Question 9

What is splicing

Answer 9

Affects a splice site
Leads to an intron being removed incorrectly

Question 10

What happens if there is a mutation in a promoter

Answer 10

Affects rate of transcription

Question 11

What happens if there is a mutation in a regulatory region or operator site

Answer 11

Gene regulation failure

Question 12

What happens if there is a mutation in the untranslated regions of 5’ or 3’ end

Answer 12

Disrupts mRNA translation / stability

Question 13

Mutation in transfer RNAs, micro RNAs, or long non coding RNAs

Answer 13

Leads to dysfunctional gene regulation

Question 14

What factors determine the effect of a mutation

Answer 14

• the amino acid affected
• amino acid chemical similarity
• sequence position and structure

Question 15

What is conservative replacement

Answer 15

Amino acids have similar properties
So rarely cause protein dysfunction

Question 16

What is radical replacement

Answer 16

Amino acids have different properties
So there is a change in phenotype or pathogenicity is caused

Question 17

What is a loss of function gene

Answer 17

Mutation that reduces or prevents gene expression

Question 18

What is the effect of a loss of function mutation

Answer 18

Dysfunction or complete loss (null or amorphic)

Often recessive

Question 19

What is a gain of function mutation

Answer 19

Mutation causing new or abnormal function

Often dominant

Question 20

What are chromosome aberrations

Answer 20

Aneuploidies

Changes to chromosome number or structure

Question 21

Structural chromosome aberrations

Answer 21

Translocation
Inversion
Insertion
Amplification
Duplication
Deletion

Question 22

Numerical chromosome aberrations

Answer 22

Loss or gain of function mutations of a whole chromosome set

Question 23

What is haploinsufficiency

Answer 23

Where one allele is inactivated by a mutation

So only one functional copy remains

Question 24

What is the effect of haploinsufficiency

Answer 24

The remaining functional copy doesn’t have enough product to be ‘normal’

Causes an abnormal or decreased state

In some autosomal dominant disorders

Question 25

What is a dominant negative mutation

Answer 25

Where the non- functional allele does the opposite function to the normal wild type

Can cause phenotypic change like cancer tumours