Most important questions: Flashcards
What is population substructure?
When the allele frequency is not uniform in the population. The expected value of alleles is different for different people in the population.
The p will often be the same but the variance will change.
What happens if the conditions for HWE are met?
The genotype distribution is defined by the allele frequency.
What are aggregation and heritability analysis used for?
To show if a phenotype has a genetic basis.
What is segregation analysis used for?
To find evidence of a specific genetic model.
The basis of aggregation analysis:
Aggregation analysis is based on mendels first law: the genetic material in a family has an equal probability of being passed down to children.
What does heritability analysis investigate?
The using quantitative data it assesses the amount of variation atrributable the genetic component in relation to total variation.
What is the idea behind segregation analysis?
to test and compare genetic models based on phenotypic data.
genetic model incapsulates mode of inheritance (e.g dominant) and number of ‘DSLs.
Calculates a likelihood of each model and compares.
What do you try to figure out when using gene mapping?
You try to find the position of a disease gene.
What is the principle behind linkage analysis?
In families, marker-gene associations can be found over large distances since a large proportion of the genetic material is shared.
The goal is to assess if an observed genetic marker locus is physically linked to the disease locus. H0 = theta = 1/2.
What is the principle behind association mapping?
In unrelated subjects the markers have often been recombined a lot so we only see association between genes and markers that are very close.
The objective is to establish an association between two variables: disease trait and a genetic marker.
What is required for both linkage and association?
A marker map.
What is a linkage map?
A map that describes the relative position of markers based on their recombination fraction.
What does parametric linkage mean?
Phenotype as a function of th egenetic marker and its distance to disease locus using a full parameterized statistical model.
