Mutations
1. Mutation is a change in the nucleotide
sequence
2. A mutation is an unpredictable and
permanent change in DNA
3. Mutations are random
There are 4 types of DNA mutations:
1.
2.
3.
4.
Substitution
Insertion
Deletion
Frame-Shift Mutation
Substitution
1. A mutation that exchanges one base for
another
2. A different codon, makes a different protein
3. Example – Sickle Cell Anemia
1. Inherited disease of red blood cells
2. Symptoms: pain, fatigue, breathlessness,
rapid heart rate
3. Prognosis: Incurable. Some patients may
live into their 50’s
Insertion
1. Mutations in which extra base pairs are
inserted into a new place in the DNA
2. Different codon, different protein
3. Example – Huntington’s Disease
1. Huntington's disease is an inherited disorder
in which some brain cells waste away, or
degenerate.
2. Symptoms: Uncontrollable body
movements, Dementia, Disorientation.
3. Prognosis: Incurable. Death by 15-20 years
old.
Deletion
2. Different codon, different protein
3. Example - Cri du Chat Disease
1. Cri du Chat disease is a
genetic disorder caused by a
missing piece of
chromosome #5.
2. Symptoms: Severe mental,
speech, and motor delays.
3. Prognosis: Many will have
normal life expectancy.
Frameshift
1. A genetic mutation caused by a deletion or
insertion in a DNA sequence that shifts the
way the sequence is read.
2. Different codon, different protein
3. Example – Tay-Sachs Disease
1. Inherited as a recessive gene
2. Symptoms: A relentless
deterioration of mental and
physical abilities
3. Prognosis: Usually results in
death by the age of four.
1. Radiation includes x-rays, radioactivity
from nuclear power plants, and UV
radiation from the sun.
2. In large doses, radiation is a proven cause
of cancer and death.
3. Tanning is the body’s defense against UV
radiation because exposure to UV
radiation can cause cancer.
1. Mutagenic chemicals are chemicals that
cause genetic mutations which often lead
to cancer and death.
2. Example: BPA in plastic food
containers including water bottles.