4.7 MCB - Genetics of Multifactorial Disorders Flashcards
Match the word with its description:
Amorph/ nullimorph A) reduced function of gene
Hypomorph B) increased function of gene
Hypermorph C) total loss of function
Amorph/nullimorph - total loss of function.
Hypomorph - reduced function of gene.
Hypermorph - increased function of the gene.
You have a gene that when activated stimulates the cell cycle, this is an example of:
amorph
hypomorph
hypermorph
Hypermorph.
Protoonco gene.
You have a gene that when deactivated causes the cell to proliferate out of control, this is an example of:
Amorph
Hypermorph
Hypomorph
Hypomorph.
Tumor suppressor gene.
Match the term with its definition:
Antimorph A) creates a new effect or product
Neomorph B) starts good, gets lame
Neo-morpheus C) creates an antagonistic effect
Antimorph - creates antagonistic effect.
Neomorph - creates a new effect or product.
Neo-morpheus - starts good, gets lame.
What does the term epistasis refer to?
Phenomenon of one gene being dependent on the presence of one or more “modifier genes”.
A new pt. to your office tells you that they were diagnosed with high blood pressure 2 years prior. This information tells you that your patient has a disease that is made up of qualitative or quantitative traits?
Quantitative.
Quantitative traits: a lot or a little, polygenic = more than one gene influencing this.
A baby is born with epilepsy this is an example of a qualitative or quantitative trait?
Qualitative.
Qualitative traits: all or nothing. Monogenic.
The first step in genetic analysis of qualitative disease traits is to find a pedigree that demonstrates familial aggregation. What does this mean?
Find a pedigree in which there is, a family cluster of individuals affected by a disease with complex inheritance.
Define concordance and discordance.
Concordance: 2 family members have the same disease.
Discordance: 1 family member is affected but the other is not.
Is concordance proof of shared inheritance of disease causing alleles, why or why not?
No.
Environmental influences may outweigh the absence of predisposing alleles in one individual to yield the diease.
However, is discordance proof that the disease is environmental, why or why not?
No.
Predisposing genetic factors may be present in both, but one may not have experienced the right environmental conditions to manifest the disease.
What is relative risk a measurement of? Give the equation. What does a high number mean, low number?
Relative risk: a measurement of familial aggregation.
Relative risk = (prevalence of disease among relatives of infected person) / (prevalence of disease among general population).
High # = lends itself to being a more genetic disease.
Low # = lends itself to being less genetic.
Would a common or rare disease have coincidental familial aggregation?
Common = more coincidental familial aggregation.
If the relative risk is high, is the disease definitely genetic, why or why not?
No.
Could be completely environmental.
Would you expect concordance to be greater or less with more closely related relatives?
Greater.
