Chapter 10

Question 1

What is a complex trait?

Answer 1

Believed to result from variation within multiple genes and their interaction with behavioral and environmental factors, also are traits that do not behave according to simple Mendelian inheritance laws.
- examples: disorders such as autism, cancer, diabetes.

Question 2

How many genes do we expect to affect a complex trait?

Answer 2

Result from variation within multiple genes and their interaction with behavioral and environmental factors.

Question 3

Why do we use SNPs instead of the whole DNA sequence?

Answer 3

We use SNPs to help predict an individual’s response to certain drugs and risk of developing diseases. They can actas biological marker, helping scientists locate genes that are associated with disease.

Question 4

Haplotype

Answer 4

A set of DNA variants along a single chromosome that tend to be inherited together. They can be found very dose to one another on the chromosome.

Question 5

How can we use haplotypes to study population structure and disease?

Answer 5

Scientists can identify patterns of genetic variation that are associated with health and disease states. The haplotype tracts assessed with common GWAS arrays can provide insight into both population history and rare disease.

Question 6

Why can’t we learn everything about a single trait with a genome-wide association study?

Answer 6

This is because individual loci likely have weak associations with the trait in question, meaning that at smaller sample sizes they blend in with the natural mosaic of back ground genetic variation.

Question 7

Steps of the GWAS

Answer 7

1. Identify the markers
2. Identify the phenotypes
3. Run a test to test association
4. Calculate p-values
5. Take the -log10 of the p-value
6. Create a manhattan plot