Lecture 19 - Mutations I Flashcards
Tinman gene mutation often causes what?
Heart defects
Mutation of this gene were identified among 608 patients with congenital heart defects.
NKX2.5
Describe somatic mutations
Arise in tissue other than germ-line and impact is restricted to the individual
Describe germ-line mutations
Arise in tissues that produce gametes and can be passed on to offspring.
Are gene mutations always harmful?
No
What is a De novo mutation?
An alteration in a gene that is present for the first time in a family member. Due to a mutation in a germ cell of one of the parents or in the fertilized egg itself. can be either germ line or somatic
What is a transition base substitution?
Substitution of a purine for a purine or a pyrimidine for a pyrimidine.
What is a transversion base substitution?
Substitution of a purine for a pyrimidine or a pyrimidine for a purine.
What are trinucleotide repeat mutations?
When extra trinucleotide sequences are added due to hairpin structures forming.
What is a loss of function mutation?
Causes the complete or partial absence of a normal protein function. USUALLY RECESSIVE
What is a neutral mutation?
Missense mutation that alters the amino acid sequence but does not change the function of the protein.
What is a Silent mutation?
Mutation that a changes the codon sequence but not the amino acid sequence.
What is a missense mutation?
Base substitution that results in a different amino acid
What is a nonsense mutation?
Mutation that changes a sense codon into a termination codon.
What is a forward mutation?
Mutation that alters the wild-type phenotype
What is a Reverse mutation?
Mutation that changes the mutant phenotype back into the wild-type.
What is a Gain of function mutation?
Produces an entirely new trait or causes it to appear in an inappropriate tissue or at an inappropriate time.
What is a suppressor mutation?
Genetic change that hides or suppresses the effect of another mutation
Intragenic suppressor mutations occur where?
Same gene
Intergenic suppressor mutations occur where?
Different genes
An individual that has both the original mutation and the suppressor mutation will display which phenotype?
Wild-type
Insertion?
Addition of one or more nucleotides
Deletion?
Deletion of one or more nucleotides
Frameshift mutation?
Insertion or deletion that alters the reading frame of a gene.
In-frame deletion or insertion?
Deletion or insertion of a multiple of three nucleotides that does not alter the reading frame
Expanding nucleotide repeats?
Increases the number of copies of a set of nucleotides
