Lecture 9 - Study Design

Question 1

What are the 5 steps you need to plan in a genetic study?

Answer 1

What is the aim?
Who are the cohort?
How will the data be gathered?
How will the data be analysed?
What is the utility of the results?

Question 2

What are the 3 types of data gathering?

Answer 2

Candidate gene studies
GWAS
WGS/WES

Question 3

What are the advantages of candidate gene studies?

Answer 3

Quite a high likelihood of finding a genotype/phenotype association
Cost effective

Question 4

What are the disadvantages of candidate gene studies?

Answer 4

Biased approach

Not likely to uncover novel gene associations

Question 5

What are the advantages of GWAS?

Answer 5

Unbiased approach
Looks at whole genome so likely to uncover novel variants
Low cost

Question 6

What are the disadvantages of GWAS?

Answer 6

Not likely to uncover rare variants
Lots of data needed
High computer processing power needed

Question 7

What are the advantages of WGS/WES?

Answer 7

Unbiased approach
Likely to detect rare variants
Looks at whole genome so likely to uncover novel variants

Question 8

What are the disadvantages of WGS/WES?

Answer 8

Lots of data required

Can only read short sequences at a time, so not useful for identifying large INDELs or CNVs

Question 9

How is a candidate gene study carried out?

Answer 9

Study associations between gene variants of a pre-specified gene of interest, and the phenotype

Question 10

How is a GWAS carried out?

Answer 10

Using a large population with varying phenotypes
Many of their genetic variants are read using SNP arrays
Look for variants that occur more frequently in people with the disease

Question 11

How is WGS/WES carried out?

Answer 11

Sequence the whole genome (or exome) of a few people with the phenotype of interest