Mutation

1. MUTATIONS
Changes in genetic code

2. MUTATION
• the action or process of mutating.
• Changes in Genetic Code
• A mutation is a change that occurs in our DNA sequence, either due to
either due to mistakes when the DNA is copied or as the result of
result of environmental factors such as UV light and cigarette smoke.

3. CAUSES OF MUTATION
• 1. Spontaneous mutation
• Spontaneous mutations arise from a variety of sources, including errors in DNA
replication
• An error in DNA replication can occur when an illegitimate nucleotide pair (say, A–C)
forms in DNA synthesis, leading to a base substitution.
• 2. Induced mutations
• A mutation is any change in a DNA sequence that can be passed from parent to
offspring.
• By inducing mutations, scientists have been able to increase genetic variation,
which breeders depend on to produce crops with desirable traits, such as resistance
to diseases and insects.

4. TYPES OF MUTATION
Gene mutation Chromosomal mutations

5. GENE MUTATION1. Point Mutation
• a mutation affecting only one or very few nucleotides in a gene sequence.

6. GENE MUTATION
• 1. Frame shift Mutation
• A frameshift mutation is a genetic mutation caused by a deletion or insertion in a DNA
sequence that shifts the way the sequence is read.
• DNA (or RNA) nucleotide sequences are read three nucleotides at a time in units called
codons, and each codon corresponds to a specific amino acid or stop signal.

7. CHROMOSOMAL
MUTATION
• Deletion
• genetics, a deletion (also called gene deletion, deficiency, or deletion mutation). Deletion
is a mutation (a genetic aberration) in which a part of a chromosome or a sequence
of DNA is lost during DNA replication

8. DISORDER• Jacobsen Syndrome
• Jacobsen syndrome is a condition caused by a loss of genetic material from chromosome
11. Because this deletion occurs at the end (terminus) of the long (q) arm of chromosome
11, Jacobsen syndrome is also known as 11q terminal deletion disorder.

9. CHROMOSOMAL
MUTATION• Duplication
• A segment of genes is copied twice and added to the chromosome in duplication.

10. DISORDER
• Charcot-Marie-Tooth disease
• Charcot-Marie-Tooth (CMT) disease is the most common inherited neuromuscular disorder.
It is characterized by inherited neuropathies without known metabolic derangements.

11. CHROMOSOMAL
MUTATION• Inversion
• An inversion is a chromosome rearrangement in which a segment of a chromosome is
reversed end to end.

12. DISORDER
• Four Ring Syndrome
• Ring chromosome 4 is a rare disorder that is typically characterized by loss (deletion) of
genetic material from both ends of the 4th chromosome and joining of the chromosomal
ends to form a ring.

13. CHROMOSOMAL
MUTATION• Insertion
• A type of mutation characterized by the insertion of one or few nucleotide base pairs to a
chromosome.

14. CHROMOSOMAL
MUTATION• Translocation
• Chromosomal translocation, that is a chromosomal segment is moved from one position to
another, either within the same chromosome or to another chromosome.

15. CHROMOSOMAL
MUTATION• Non-disjunction
• failure either of two homologous chromosomes to pass to separate cells during the first mei
otic division, or of the twochromatids of a chromosome to pass to separate cells during mit
osis or during the second meiotic division.

16. DISORDER
• Down’s Syndrome
• Down syndrome is a genetic disorder and the most common autosomal chromosome
abnormality in humans, where extra genetic material from chromosome 21 is transferred to
a newly formed embryo.

17. DISORDER
• Klinefelter’s Syndrome
• Klinefelter syndrome is a chromosomal condition that affects male physical and cognitive
development.

18. DISORDER
• Turner’s Syndrome
• Turner syndrome is a chromosomal condition that affects development in females.

19. DIAGNOSING GENETIC
DISORDERS
• There are several ways to determine whether a
• child will have a genetic disorder
• Two main ways to diagnose:
• Analysis of fetal cells
• Amniocentesis
• Chorionic villus biopsy
• Imaging techniques
• Ultrasonography (computerized image)
• Fetoscopy (direct observation

20. REFERENCE LIST
• Jevz, D (2018) Hereditary. Available from Slideshare at
https://www.slideshare.net/JEvzOlliuqNobrac (Accessed 30 August 2018)