Molecular Identification of Somatic Mutations in Cancers Flashcards
(191 cards)
Stochastic
Randomly occurred
Genetic Drift
Variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce.
Punctuation (tumor growth)
A catastrophic event that induces a radical change in phenotype, typically followed by strong selection for that phenotype.
Chromothripsis
A mutational process of clustered chromosomal rearrangements occurs in a single event in localized and confined genomic regions in one or a few chromosomes,
Chromoplexy
Multiple chromosomes are involved in chains of translocations.
Kataegesis
Localized hypermutation resulting in many single-base-pair changes in a small region.
Linear Evolution
The process where successively fitter mutants arise and sweep to fixation, replacing less fit lineages.
Branched Evolution
Multiple subclones, each with different selective growth advantages and effectively a distinct phenotype, co-occur within the tumor.
Neutral Evolution
New mutations confer no fitness advantage, and
lineage size is determined by time of emergence. The absence of selection.
Fitness
In tumors, it is intuitively understood as the net growth rate of lineages relative to other lineages.
Mechanistic
In purely physical terms.
Proliferation
The ability of cells to evade the homeostatic regulation of physiologically normal tissues.
Negative Selection
Also known as purifying selection. When subclones that have reduced fitness are more likely to be lost or remain at low frequencies within the population. This type of selection is particularly important in the context
of how the immune system interacts with cancer cells and is critical for predicting the efficacy of
immunotherapy.
Neoantigens
Mutations that cause cell surface markers that can be recognized by the immune system.
Subclone
A subpopulation of cells that descended from another clone but then diverged by accumulating another driver mutation.
Genome Doubling
A common feature of cancer evolution (∼30% of cases) and is thought to be a driver of copy number instability.
Passenger Mutations
Mutations that do not provide a selective growth advantage, and thus do not promote cancer development.
Structural Variants
Large genomic alterations, encompassing at least 50 bp.
Copy Number Alterations
Somatic changes to chromosome structure that result in gain or loss in copies of sections of DNA, and are prevalent in many types of cancer.
Hypermutation
Mutation that is abnormally frequent.
Somatic
Originating in the body.
Germline
The cells that form the egg, sperm and the fertilized egg.
Synonymous Mutation
A change in the DNA sequence that codes for amino acids in a protein sequence, but does not change the encoded amino acid.
Nonsynonymous Mutation
A change in the DNA sequence that codes for amino acids in a protein sequence and does change the encoded amino acid.