Pharmacogenetics and Complex Traits

Question 1

What is a single nucleotide polymorphism?

Answer 1

A single nucleotide polymorphism, or SNP (pronounced “snip”), is a variation at a single position in a DNA sequence among individuals.

If more than 1% of a population does not carry the same nucleotide at a specific position in the DNA sequence, then this variation can be classified as a SNP. If a SNP occurs within a gene, then the gene is described as having more than one allele.

Although a particular SNP may not cause a disorder, some SNPs are associated with certain diseases. These associations allow scientists to look for SNPs in order to evaluate an individual’s genetic predisposition to develop a disease.

Question 2

How are SNPs established?

Answer 2

Association analysis

Question 3

What is done to make a genome wide study effective?

Answer 3

Shorter process only 10,000,000 snips as nucleotides next to one another often have a common link
Agnostic search no bias for a single SNP
Needs a large sample size
Forms Robust findings

Question 4

What p value do you use in a genome wide study?

Answer 4

1*10^-8 as so many tests are being done compared to the usual 0.05

Question 5

How many genes do monozygotic twins share (%)

Answer 5

100%

Question 6

Causes of missing heritability

Answer 6

Rare (SNPs)
Low frequency variants with intermediate effect •
Interactions • Miscalculated estimation of heritability
Diagnosis (accuracy and precision)

Question 7

What is pharmacogenetics?

Answer 7

The study of variability in drug response due to genetic differences

Question 8

A healthy 2-year-old boy went under tonsillectomy and received codeine after discharge from hospital to control pain. The dose was standard for his age and sex and was administered as prescribed. Few days later, he died of the respiratory side effect of codeine. Q. What do you think went wrong?

Answer 8

Child had a duplication of an allele so has a significant reaction causing death. This is a pharmocogenetic affect.