Molecular Mechanisms Flashcards
Novel property mutations definition
Mutation that confers a novel property on the protein without necessarily altering its normal functions
Sickle cell disease affects the ____ of hemoglobin
Structure
Sickle cell disease illustrates molecular mechanism of a ____ ____ mutation
novel property
Why is sickle cell disease considered a novel property mutation?
Change in the amino acid sequence causes pathology by conferring a novel property on the protein without necessarily altering its normal function
Population genetics is the study of the distribution of ______ in populations
and of how the frequencies of alleles and genotypes are maintained or changed
- alleles
Genetic drift is defined as fluctuations in the _______ of alleles resulting from chance occurrences operating in small populations
-frequency
Founder effects is defined as the [random/nonrandom] distribution of alleles among the individuals who founded particular subpopulations
-nonrandom
In what kind of conditions will you use Hardy-Weinberg approximation?
Autosomal recessive, rare diseases
In the approximation method, how do you determine q?
Take the square root of prevalence
In the approximation method, p is about equal to __
1
The _______ frequency is about twice the minor allele frequency, which is twice the square root of the prevalence
carrier; 2q
In Hardy-Weinberg equilibrium, what are the assumptions that are made?
- Large population
- Random mating
- No selective pressures
- No immigration of different alleles
- No mutations
Stratification
Population that contains a number of subgroups that have remained genetically separate during modern times
Ex: African Americans mating with other African Americans and not Caucasians
Assortative mating
Choice of a mate because the mate possesses some particular trait
Ex: deaf person mating with another deaf person
Consanguinity
Mating with someone who is related by descent
What are some exceptions to a constant allele frequency?
- Selection for or against alleles
- Mutations
- Migration
Which genotype of sickle cell disease confers resistance to malaria and results in a higher fitness than the other alleles?
Sickle cell trait (SC); reproduction is at a higher rate
Thalassemias illustrate the molecular mechanisms of ___ _ ____ and gene dosage effects
- loss of function
What is the genetic inheritance pattern of thalassemias?
Autosomal recessive
Most common forms of alpha thalassemia are the result of ______
deletions
Over 200 mutations are described to cause B thalassemias, this is an example of [allelic/locus] heterogeneity
- Allelic
In B thalassemias, the mutations that occur are mostly missense, nonsense, and ______ mutations
-frameshift
Hereditary persistence of fetal hemoglobin occurs due to _____ mutations in the promoter region of the γ globin genes
- point
Hereditary persistence of fetal hemoglobin illustrates _______ or ectopic gene expression
- heterochronic (Inappropriate expression of a gene at an abnormal time or place)
The most common inherited cause of deep vein thrombosis is
Factor V Leiden
Activated protein __ usually would degrade factor V in the clotting cascade
C
In factor V leiden, the expression of the phenotype is influenced by the ______
- Environment
What is the pattern of inheritance for Factor V Leiden?
Autosomal dominant
Haploinsufficiency refers to _____ phenotypes
- dominant
Loss of half of the normal activity of a protein causes disease refers to
Haploinsufficiency
Abnormal protein causes an abnormal phenotype by interfering with the function of the product of the normal allele refers to
Dominant negative effect
One gene has multiple phenotypic effects, particularly when the effects are not obviously related refers to
Pleiotropy
Severity of expression of the phenotype, although there is always some degree of expression present refers to
Variable expressivity
Probability that a gene will have any phenotypic expression refers to
Penetrance
