Changes in the nucleotide sequence of genes that appear to have no known causes
Induced mutations
Mutations that result from the influence of extraneous factors
Mutation rate
The likelihood that a gene will undergo a mutation in a single generation
Mutation hot spots
DNA sequences that appear to be highly susceptible to mutation
Somatic Mutations
Mutations occurring in any cell in the body except germ cells
Autosomal mutations
Mutations within genes located on the autosomes
X and Y linked mutations
Mutations in genes located on the X or Y chromosome
Point mutation or Base substitution
A change of one base pair to another in a DNA molecule
Missense Mutation
When a change of one nucleotide of a triplet within a protein coding portion of a gene results in the creation of a new triplet codon that codes for a different amino acid
Nonsense Mutation
When a triplet codon is changed into a stop codon, resulting in the termination of translation of the protein
Silent mutation
When a point mutation alters a codon but does not result in a change in the amino acid
Transition
When a pyrimidine replaces a pyrimidine
or
When a purine replaces a purine
Tranversion
When a pyrimidine replaces a purine
or
When a purine replaces a pyrimidine
Purines
Adenine & Guanine
Pyrimidines
Cytosine
Thymine
Uracil
Frameshift mutation
The addition or deletion of any base causes all of the triplets downstream to be off or changed
Null mutations
A loss-of-function mutation that results in complete loss of function
Gametic mutations
Mutations that happen in the germ-line and can be passed on