Mutation is a permanent change in an organism's genome that can occur at the single nucleotide level through point mutations like substitutions, transitions, and transversions, or through insertions, deletions, and frameshift mutations. Mutagens are agents like radiation or chemicals that cause genetic mutations. Various techniques can detect mutations, including single strand conformational polymorphism and heteroduplex analysis. Examples of genetic disorders caused by mutations are Down syndrome from improper chromosome 21 separation and cri-du-chat syndrome from a deletion on chromosome 5.

1. Mutation
Venkatesh Karthikeyan
Email : 4852012@gmail.com

2. Definition:
 Mutation is a sudden,permanent
change in the nucleotide sequence of
the genome of an organism, virus, or
extrachromosomal DNA or other genetic
elements.

3. Mutagens:
 An agent, such as radiation or a
chemical substance, which causes
genetic mutation.

4. Point Mutations:
 It is a single base modification
 Substitution is a point mutation

5. Substitution:
 A substitution is a mutation that
exchanges one base for another.
 Example:
○ THE FAT CAT ATE THE RAT
○ THE FAT HAT ATE THE RAT

6. Substitution:
 Transition mutation
 Transversion mutation

7. Transition mutation
 A transition is a point mutation that changes
a purine nucleotide to another purine (A ↔ G)
or a pyrimidine nucleotide to another
pyrimidine (C ↔ T).

8. Transversion Mutation:
 Transversion refers to the substitution
of a purine for a pyrimidine or
conversely in DNA.

10. Frameshift mutation:
 A frameshift mutation is a genetic
mutation caused by insertions or
deletions of a number of nucleotides in a
DNA sequence that is not divisible by
three.

11. Insertion:
 A type of mutation resulting from the
addition of extra nucleotides in a DNA
sequence or chromosome.
 Example:
○ THE FAT CAT ATE THE RAT
○ THE FAT CAT XLW ATE THE RAT

12. Deletion:
 A type of mutation resulting from the
deletion of nucleotides in a DNA
sequence or chromosome.
 Example:
○ THE FAT CAT ATE THE RAT
○ THE FAT CAT ___ THE RAT

13. Mutation Detection Techniques:
 Single Strand Conformational Polymorphism (SSCP)
 Heteroduplex Analysis
 Conformation Sensitive Gel Electrophoresis (CSGE)
 Protein Truncation Test (PTT)
 Denaturing High Performance Liquid Chromotography
(DHPLC)
 Ame’s test to detect mutagenicity

14. Down Syndrome
 Chromosome 21 does not
separate correctly.
 They have 47
chromosomes in stead of
46.
 Children with Down
Syndrome develop slower,
may have heart and
stomach illnesses and
vary greatly in their
degree of inteligence.

15. Cri-du-chat
 Deletion of material
on 5th chromosome
 Characterized by
the cat-like cry
made by cri-du-
chat babies
 Varied levels of
metal handicaps

16. M̀ hgòi 