This presentation consists of mutations and its types - Genomic, chromosomal and gene mutations. Along with it, there is a figurative explanation of Haemophilia, sickle cell anaemia, Phenylketonuria, Down's Syndrome, Klinefelter's syndrome and Turner's Syndrome.

2. MUTATIONS
1. Any undesirable change in the sequence of the genetic material is called mutation
2. These changes can either be beneficial or harmful for the organism
3. The term mutation was given by the scientist Hugo de Vries
4. Mutations can be divided into three types
Gene mutation Chromosome mutation Genome mutation
Genome- Total genetic material present in the cell of an organism
Ploidy (n) - the no.of sets of chromosomes inside a cell
Haploid (n), Diploid (2n), Triploid (3n), Tetraploid (4n), Hexaploid (6n)

3. Gene- The part of a genetic material which expresses itself is called gene
GENOME MUTATION
EUPLOIDY
1. Presence of chromosomes in
multiples of haploid number
(n)
2. Eg- diploidy (2n), triploidy
(3n), tetraploidy (4n)
ANEUPLOIDY
1. addition or deletion of one or
more chromomes.
2. Classified into two categories
Mother = 23 (n)
Father = 23 (n)
Diploid zygote = 46 (2n) -diploid
a. Addition of chromosomes
1. Trisomy- addition of only one chromosome in the
diploid pair. (2n+1) – Down’s syndrome (trisomy of
chromosome 21), Klinefelter’s syndrome (trisomy of
X-chromosome)
2. Tetrasomy- addition of two chromosomes in the
diploid pair. (2n+2)
b. Deletion of chromosomes-
1. Monosomy- Deletion of only one
chromosome from the diploid pair. (2n-1)-
Turner’s syndrome (monosomy of X-
chromosome)
2. Nullisomy- Deletion of two chromosomes
from the diploid pair. (2n-2)

4. Chromosome mutation
Centromere
P-arm
Q-arm
Loci/locus-
The location
of a gene on
the
chromosome
A
b
c
Tpes of chromosomal mutations-
1. Duplication- duplication of a part of the chromosome
2. Deletion- Deletion of a part of the chromosome
3. Inversion- parts of chromosomes are inverted
4. Translocation- part of one chromosome is transferred onto
another chromosome

5. POINT MUTATIONS
Point mutations occur due to alterations in a single base wherein one of the nitrogenous bases is replaced with another
base. Based on the nature of bases being replaced, point mutations are of two types-
1. Transition- Replacement of purine by another purine and pyramidine by another pyramidine
2. Transversion- Replacement of purine by a pyramidine and vice versa

6. FRAME SHIFT MUTATION
Occurs due to insertion or deletion of a nucleotide which causes a
change in the reading frame of the mRNA
AUG AAA UUU CTC GUA CCC TTT – Normal reading frame
AUG AAA UUU CTC GUA CCC TTT – deletion of A from the second codon pair
AUG AAU UUC TCG UAC CCT TT… - Changed reading frame
AUG AAAG UUU CTC GUA CCC TTT – Insertion of G in the second codon pair
AUG AAA GUU UCT CGU ACC CTT T... – changed reading frame

7. Disorders to discuss-
1. Haemophilia- Gene mutation
2. Sickle cell anaemia- Gene mutation
3. Phenylketonuria- gene mutation
4. Down’s syndrome- Genome mutation- Trisomy of chr 21
5. Klinefelter’s syndrome- Genome mutation- Trisomy of chr X
6. Turner’s syndrome- Genome mutation- Monosomy of chr X
Mendelian disorders:
Those disorders where Mendel’s
pattern of inheritance can be
observed and Mendel’s laws are
followed are called Mendelian
disorders

8. HAEMOPHILIA
It is also known as Royal Disease because it was diagnosed for the first time in the British royal
family
1. It is a heritable mutation- It can be inherited from one generation to another generation
2. It occurs in the X-chromosome
3. It must be present in a homozygous recessive or hemizygous (presence of only one copy of the
chromosome) condition to express itself.
4. It is an X-linked (mutations occurring in genes located on X chr) recessive mutation
5. The patient suffering from Haemophilia does not show clotting of blood like a normal healthy individual in
other words it shows excessively delayed clotting of blood.
6. Defects in genes producing either Clotting factor VIII (Haemophilia A) or Clotting Factor IX (Heamophilia
B) are the causes of HAEMOPHILIA

9. In females
XHXH- Healthy condition
XHXh - Carrier condition
Xh Xh - Infected condition
In males (hemizygous for X-chromosome)
XHY- Healthy condition
Xh Y- Infected condition
Alleles- alternative forms of a same gene. One of the alleles is dominant and the
other allele is recessive
Dominant- H-XH
Recessive – h- Xh
XHXH
XH XH
XHXh
XH Xh
XhXh
Xh Xh
Healthy female
Produces normal
Clotting factors
Carrier female
Produces normal
Clotting factors
Diseased female
Defective clotting factors

10. XHY
XH Y
XhY
Xh Y
Healthy male
Clotting is normal
Diseased male
Abnormal clotting
Haemophilia is also known as Criss-Cross inheritance-
father to Daughter to Grandson with skipping of a
generation

11. XH
XH
XH
Y
Mother
Father
XH XH XH Y
x
XHXH XHXH XHY XHY
Case 1
XHXH- NORMAL FEMALE
XHY- NORMAL MALE

12. XH
Xh
XH
Y
Carrier
Mother Father
XH Xh XH Y
x
XHXH XHXh XHY XhY
Case 2
XHXh- Carrier FEMALE
XHY- NORMAL MALE
F1 GENOTYPES
XHXH- NF
XHXh- CF
XHY- NM
XhY- DM

13. Xh
Xh
XH
Y
Diseased
Mother Father
Xh Xh XH Y
x
XHXh XHXh XhY XhY
Case 3
XHXh- Diseased FEMALE
XHY- NORMAL MALE
F1 GENOTYPES
XHXh- CF
XhY- DM

14. Xh
Xh
Xh
Y
Diseased
Mother
Diseased
Father
Xh Xh Xh Y
x
XhXh XhXh XhY XhY
Case 4
XHXh- Diseased FEMALE
XHY- Diseased MALE
F1 GENOTYPES
XhXh- DF
XhY- DM

15. SICKLE CELL ANAEMIA
• Haemoglobin- it is the chief oxygen transporter in the body
• It is a protein molecule (polypeptide chain)
• It has 4 subunits- it contains 4 polypeptide chains
• There are two types of globin protein- a-globin and b-globin
• Haemoglobin is made up of 2 a-globin units and 2 b-globin units
Structure - Heme group
Hb = Heme + globin
Location-
Chromosome= 11
Arm= p
Locus= 15.5
It is an autosomal disorder

16. • This condition occurs due to a point
mutation in b-globin gene (chr 11p15.5)
• GAG which codes for Glutamic acid is
replaced by GUG which now codes for
Valine
5’-GAG-3’- mRNA
5’-GUG-3’ – mutated mRNA
3’-CTC-5’ – template
3’-CAC-5’ – mutated template
(transversion point mutation)
Problems of sickle shaped RBCs
• RBCs cannot move freely in the blood vessels
• RBCs tend to form clots/ block the blood
vessels
• The Oxygen transporting capacity of RBCs is
reduced
• Shortness of breath
• Muscular fatigue- pain and tiredness of
muscules

17. PHENYLKETONURIA
• It is an autosomal recessive disorder
• It occurs on Chromosome 12q23.2
• It occurs due to mutation in PAH gene (PAH= Phenylalanine Hydroxylase)
• PAH gene codes the mRNA for translation of Phenylalanine hydroxylase
• The enzyme Phenylalanine Hydroxylase helps in conversion of Phe amino acid to Tyr amino acid
• Due to absence of the enzyme Phe is not converted in to Tyr and it is accumulated as
phenylketopyruvate
• Phenylketopyruvate is toxic for the body (neurotoxic). Hence this leads to mental retardation.
• In absence of Tyr, melanin pigment is not formed. In absence of melanin, albinism can be observed
• Symptoms of PKU
1. Mental retardation
2. low social skills
3. Low ability to read/write/speak
4. white to patchy hairs, skin and eyes
Location-
Chromosome= 12
Arm= q
Locus= 23.2

19. DISORDERS OCCURING DUE TO NON-DISJUNCTION OF CHROMOSOMES
NON-DISJUNCTION-
• It is the failure of separation of chromosomes from each other during
anaphase 1 of meiosis 1 during cell division.
• As a result of non-disjunction, one cell receives two copies of a
chromosome while the other cell does not receive any copy of that
chromosome.
For example-
• If the maternal and paternal chromosomes of chromosome 21 in a cell fail to separate during
gametogenesis one of the gametes will receive both copies of chromosome 21 while other gamete will
have no chromosome 21.
• So If the gamete with 2 copies of Chr 21 fuses with a normal haploid gamete with 1 copy of Chr 21, the
resulting zygote will have 3 copies of chromosome 21, causing Down’s syndrome
• Similarly If the gamete with no copy of chr 21 fuses with a normal haploid gamete with 1 copy of chr 21,
the resulting zygote will have only 1 copy of chr 21 rather, causing monosomy of Chr 21

20. XX
XX
X
XXX
X
XO
If non-disjunction occurs in a NORMAL FEMALE
Gamete receives both
chromosomes of the pair
Gamete receives no chromosome
(of that particular pair)
Healthy (normal) gamete Healthy (normal) gamete
Trisomic
zygote
Monosomic
zygote
Fertilization of gametes
Non-disjunction during ANAPHASE
1/2 followed by Telophase 1/2
Fertilization of gametes

21. REPRESENTATION OF NON-DISJUNCTION DURING CELL DIVISION
Non-disjunction during meiosis 2 Non-disjunction during meiosis 1

22. DOWN’S SYNDROME
• Trisomy of chromosome 21 (autosomal)
• Karyotyping can be used to detect this syndrome
• Karyotype is the picture representation of all the chromosomes of a cell in metaphase state of cell
division
Symptoms of Down’s syndrome-
1. Mental retardness
2. Low social skills
3. Broad forehead
4. Tongues usually out
5. Mouth usually open
6. Flat nose
7. Broad face
8. Usually Short stature

23. Adult female
Adult male
• Amniotic fluid found in amnion of the growing feotus
• The process of evaluating amniotic fluid is called
amniocentesis
• Using amniocentesis, one can perform karyotyping to
detect any existing chromosomal defects
Child suffering from Down’s syndrome

24. KLINEFELTER’S SYNDROME
• Occurs due to trisomy of X-chromosome
• The resultant individual is a male but displays certain female characteristics which may start to
develop during puberty
• It occurs when a female gamete carrying two X-chromosomes fuses with a normal male
gamete carrying Y chromosome.
• As a result of this the child contains two copies of X and one copy of Y chromosome, having the
chromosome composition of 44+XXY.
• The child develops as a male due to presence of a Y chromosome but also starts to express
female characteristics due to presence of an extra X-chromosome.

25. Symptoms of Klinefelter’s syndrome
• Taller than average height
• Longer legs, shorter upper body (torso)
• Broader (female like) hips
• Delayed puberty
• Small Penis
• Enlarged breast tissue (gynaecomastia)
• Weak bones
• Tendency to be shy and sensitive
• Decreased facial and body hairs
• Lower sex drive
• Low sperm counts or sterile

26. KARYOTYPE OF A MALE SUFFERING FROM KLINEFELTER’S SYNDROME

27. TURNER’S SYNDROME
• Turner’s syndrome occurs due to monosomy of X chromosome
• The resultant individual is a female. However, development of female characters is reduced and
delayed when compared to normal females.
• It occurs when a female gamete carrying no X chromosome (due to non-disjunction) fuses with a
healthy female gamete carrying one X chromosome.
• As a result the female carries only one X chromosome rather than a normal of two X chromosomes
thereby having a chromosome composition of 44+XO

28. Symptoms of Turner’s syndrome
• Short stature
• Some women have an extra skin on
the neck (webbed neck)
• Ovaries are underdeveloped or
rudimentary
• Sterile due rudimentary ovaries
• Puffiness of swelling of hands and
feet (Lymphedema)
• Heart defects
• High blood pressure
• Risk of kidney problems
• Slightly higher risk of thyroid disease
• Risk of developing diabetes

30. KARYOTYPE
OF
TURNER’S
SYNDROME

31. THANKYOU
Presented by
ADITYA NARAYAN SINGH
INDIAN ACADEMY DEGREE COLLEGE- AUTONOMOUS