Lecture 23: Complex disease and pharmacogenetics Flashcards
What is a mendelian trait?
a trait controlled by a single gene (inheritance follows Mendel’s principles)
What is a complex trait
a trait controlled by multiple genes and the effect of environment e.g. hair, skin, eye colour, height, weight, personality
Name some examples of complex disease.
- diabetes
- cardiovascular disease
- cancer
- asthma
- hypertension
- mental health diseases
What are single nucleotide polymorphisms?
DNA sequence variations that occur when a single nucleotide is changed - most common form of variation in human genome
How are genetics of complex traits studied?
By genome-wide association studies
What do genome-wide association studies do?
Analyse association between millions of SNPs throughout genome with a complex disease
What is heritability?
proportion of variation in population explained by genetics and inheritance rather than environmental factors
How much genetic info do monozygotic twins share?
100%
How much genetic info do dizygotic twins share?
50%
What is meant by the term ‘missing heritability’?
The “missing heritability” problem states that genetic variants in Genome-Wide Association Studies (GWAS) cannot completely explain the heritability of complex traits.
What reasons have been suggested for missing heritability?
- rare variants
- low frequency variants w/intermediate effect
- interactions
- miscalculated estimation of heritability
- diagnosis (accuracy and precision)
What is pharmacogenetics?
Study of variability in drug response due to genetic differences - to help improve drug therapy and prescribing in future
What is personalised medicine?
Tailoring treatment to patients depending on specific characteristics of their disease
How could pharmacogenetics help improve healthcare?
By increasing administration of medication with high efficacy and low side effect for patients
