Complex Diseases and Pharmacogenetics Flashcards
What are the two different types of genetic diseases?
mendelian or complex
What is a mendelian disease?
A condition with clear mendelian inheritance patterns, caused by a single gene with limited environmental influence
What is a complex disease?
A disease controlled by multiple genes, and where the phenotype is controlled by the interaction of many genes and the environment
What is an SNP?
A single nucleotide polymorphism - DNA sequence variations that occur when a single nucleotide is changed
What is the most common type of variation in a genome?
SNPs
What is meant by heritability?
It is an estimation of the genetic contribution to increased risk of disease
What are the two ways to measure heritability?
Twin Studies and Genome Wide Association studies
What are Genome Wide Association Studies?
Where you study the genomes of different people and look for an association between specific genetic variations and the different diseases that the people in the study have
What are the downsides of GWAS?
You need a very large sample size
Mass testing is required which needs money and qualified people
When are SNP’s said to be associated with certain conditions?
When SNPs are found to be more frequent in people with a disease compared to people without the disease
What specifically is GWAS lookin for?
Shared SNPs
What is meant by missing heritability?
The gap between the association found by the GWAS and what is known about the heritability of the disease
What are the 5 factors contributing to missing heritability?
- Rare SNPs
- Interactions are not taken into consideration
- Miscalculated estimation of heritability
- Diagnosis
- Low frequency variants with immediate effects
How do Twin studies work?
Since monozygotic twins share 100% of their genetic material, they can be analysed as any variation will be due to the environment, not genetics
What is pharmacogenetics?
The study of differences in response to drugs due to genetic differences amongst people
