How Do Mutations Affect Health & Tooth Development (Exam IV) Flashcards
The three nucleotide sequence (codon) that specifies different amino acids
Genetic code
Property/principle of the genetic code that many amino acids are encoded by multiple three nucleotide codons, as such- changes in t nucleic acid sequence may not alter the resulting amino acid
Degenerate/redundant genetic code
Mutation that results in increased function or new function in a protein
Gain-of-function mutation
Mutation that results in a decrease or absence of function
Loss-of-function mutation
Reduced gene dosage resulting in insufficient protein being made & diminished functioning of the cell
Haploinsufficiency
Mutation resulting in an altered protein that reduces or inhibits the function of another normal protein in the cell
Dominant negative mutation
Because genetic disorders represent a continuum of diseases, even if a disease is largely caused by the environment, there may still be ______ affecting the outcome
Genetic factors
Three examples of environmentally caused disease:
1- influenza
2- measles
3- infectious disease
Three examples of diseases that have around equally environmental and genetic influences:
1- diabetes
2- CV diseases
3- osteoporosis
Two examples of diseases that are fully caused by genetic factors:
1- cystic fibrosis
2- hemophilia A
Represent the largest portion of mutations that have been identified that relate to disease
Missense & nonsense
Mutations resulting in either- lower amounts, no function or enzyme deficiencies
Loss-of-function mutations
Haploinsufficiency is a subcategory of:
Loss-of-function mutations
Because you have two copies of each autosomal gene- if one copy is expressed & the other is not due to a disease causing mutation this is called:
Haploinsufficiency
Haploinsufficiency results in the amount of products being produced to be _____ compared to when no mutation is present
About 50%
Some haploinsufficiency mutations results in _____ while other cases it may result in ____
No disease; disease
Example of a disease caused by a haploinsufficiency mutation
Marfan’s syndrome
A mutation whose gene product adversely affects the normal wild-type gene product within the same cell, usually by dimerizing with with it
Dominant negative mutation
A dominant negative mutation is a subcategory of:
Loss-of-function mutations
In the cases of polymeric molecules such a as collagen, the dominant negative mutations are often _____ than mutations causing the production of no gene product (cancer)
More deleterious
Osteogenesis imperfection is an example of a:
Dominant negative mutation
Charcot-Marie-Tooth sensory neuropathy & Cherubism are examples of:
Gain-of-function mutations
Over 300 genes identified that have mutations associated with (3):
1- tooth patterning
2- morphogenesis defects
3- differentiation defects
As a collective group ______ genetic diseases are the most common
Craniofacial
Of all known genetic disease, craniofacial diseases account for about:
30%
Hallmark of autosomal recessive disease
Consanguineous mating
1- unaffected male
2- unaffected female
3- mating (single bar)
4- consanguineous mating (double bar)
5- identical twins
6- deceased female
7- lost pregnancy
8- affected male
9- affected female
10- fraternal twins
11- autosomal heterozygous carrier
12- X-lined carrier
What does an arrow indicate on a family pedigree
Proband (first case identified)
What cannot be ruled out even in the absence of consanguineous matings:
Autosomal recessive diseases
If the number of affected and unaffected individuals at each generational level is about 50/50, this suggests:
Dominant type of trait
To rule out if the trait is autosomal or sex-linked, you should look at:
Female to male & male to female transmission
Valuable tools in trying to categorize genetic diseases
Family pedigrees
If you see male to male transmission of a trait in affected individuals- you know the trait is NOT moving on the:
X chromosome
The developmental signaling pathways that drive ______ are also critical in the development of _____
Tooth development
Many other organs
Tooth development defects should be perhaps be thought of as a potential _______ for other ______ that manifest later in life
Risk factor
Diseases
There are numerous malocclusion syndromes that can be ____ or ____
Inherited or non-inherited
Pierre-robin, Treacher collins & Marfan’s syndrome are all examples of:
Malocclusion syndromes
