L24: multifactorial disease Flashcards
What is mutlifactorial inheritance
It is a disease contributed of polygenes and environmental factors
What are the studies for multifactorial disease
- twin studies
- familial clustering studies
- population and migration
- adoption studies
What is polygenic inheritance
When many genes make a small additive contribution to the final phenotype
What pattern does polygenic inheritance show
Continuous trait
What is a liability curve
A liability curve is made of genetic and environmental factors
What is a threshold liability
A limit to the liability curve where a person above the threshold develops the multifactorial disorder
What is an example of a multifactorial condition
Spina bifida
What are the genetic factors to Spina bifida
Celtic origin
Variation in MTHFR gene
What are the environmental factors to spina bifida
Poor socioeconomic status
Multiparity (having many siblings)
Valporic acid (epilepsy treatment)
How do we measure the recurrence risk for multifactorial conditions
By empiric risk
What is an empiric risk
The observed recurrence of families in the population
What factors increase the probability of recurrence in a particular family
- close relationship to person with condition
- high heritability of condition
- person with condition of more rarely affected sex
- multiple family members affected
How do we identify genes involved in multifactorial conditions
Association studies called Genome- wide association study
What does the genome wide association study help us to do
Allow to identify differences in single nucleotide phenotype alleles between normal and affected individuals
What are the SNPS
It is not a direct cause of disease but as a marker to show the relative risk associated with a disease
