Estimating Risk Of Inherited Disease Flashcards
What is reproductive fitness?
Ability of organism to survive long enough on pass on their genes.
Recessive conditions that are common
Sickle cell disease
Thalassaemia
Recessive genetic genes that are associated with selective pressures
Malaria resistance
Plague/ cholera resistance
De novo mutations are very common in:
Dominion ant and x-linked genes/ conditions
NOT recessive
In Dominant and S. linked disorder:
De novo mutations keep these conditions alive
If there weren’t any de novo mutations, they would die out.
Up to 1/3 of lethal x linked conditions are down to de novo mutations
Genotype frequencies
Aa
AA
Aa
Hardy - Weinberg equilibrium equilibrium
Relative frequencies of the alleles … Remain constant unless something changes .
Ideal population?
Mutation can be ignored Migration is negligible Mating is random No selective pressure Population size is large Allele frequencies are equal in the sexes.
Introduction of new alleles as a result of migration or intermarriage
Leads to a new gene frequency in hybrid population.
What % of men in the UK have Norwegian DNA?
60%
Non-random mating - assortative mating
Choosing of partners due to shared characteristics
E.g deafness and sign language
Non-random mating - consanguinity
Marriage between close blood relatives
E.g cultural pressures for inter-marrigage within clans/ religions etc
Natural selection
Gradual process by which biological traits become more or less common in a population
What is glucose -6-phosphate dehydrogenase (G6PD) deficiency associated with?
Malaria
Small populations?
More likely to get genetic drift and founder effect
