Mutation Mechanisms
A change in a single nucleotide base in the DNA sequence.
Point mutation
A mutation that results in a complete loss of function of the gene.
Null mutation
Mutations that are passed from parents to offspring through germ cells (sperm or egg).
Inherited mutation
Mutations that cause death, often before the organism can reproduce.
Lethal mutation
A substitution mutation where a purine is replaced by another purine or a pyrimidine by another pyrimidine.
Transition
A mutation that does not change the amino acid sequence of the protein.
Silent mutation
Mutations that occur in non-reproductive cells and are not passed on to offspring.
Somatic mutation
A mutation that is neither beneficial nor detrimental.
Neutral mutation
A substitution mutation where a purine is replaced by a pyrimidine or vice versa.
Transversion
A point mutation that results in a different amino acid being incorporated into a protein.
Missense
A mutation that only shows its effect when two copies of the mutant allele are present.
Recessive
A type of mutation that changes a codon to a stop codon, terminating protein synthesis prematurely.
Nonsense
Mutations caused by insertions or deletions of nucleotides that change the reading frame of the genetic sequence.
Frame shift
A mutation where the altered gene product disrupts the function of the wild-type protein through improper interactions, often forming nonfunctional complexes.
Dominant negative
A mutation that shows its effect even when only one copy of the mutant allele is present.
Dominant
Different mutations within the same gene cause the same disorder.
Allelic heterogeneity