Chromosomal Mutations

1
Chromosomal Mutations their effects
2
Karyotype

• A picture of the chromosomes of an individual or
  a species, including number, form, and size of
  the chromosomes.
• Often used to diagnosis chromosomal abnormalities.

3
Chromosomes

• Humans have 23 pairs
• 22 pairs are autosomes
• 1 pair are sex chromosomes
• (women XX, men XY)
• Chromosomes have a centromere that holds the
  chromatids (two parts of the chromosome)
  together.
• The top ½ of the chromosome is called the p arm
  and the bottom ½ is q

4
Nondisjunction Disorder

• Nondisjunction is the failure of chromosome pairs
  to separate during meiosis (making of gametes
  sex cells)
• it can cause some gametes to gain an extra
  chromosome and others to lose one
• Monosomy A chromosome having no homologue
  (matching chromosome)
• Trisomy The condition of having three copies of
  a given chromosome in each somatic (body) cell
  rather than the normal number of two.

5
(No Transcript)
6
(No Transcript)
7
Normal Male Karyotype
Normal Female Karyotype
8
Turners Syndrome
1 in 5,000 births 45 chromosomes X only 23
MonosomyNondisjunction
9
Turners Syndrome
96-98 do not survive to birth No menstruation No
breast development No hips Broad shoulders and
neck
10
Cri-Du-Chat Syndrome
1 in 216,000 births 46 chromosomes XY or XX 5
Deletion of upper arm of chromosome
11
Cri-Du-Chat Syndrome
Moon-shaped face Heart disease Mentally
retarded Malformed larynx Normal lifespan
12
Aniridia-Wilms Tumor Syndrome
1 in 50,000,000 births 46 chromosomesXY or
XX 11 Deletion of upper arm
13
Aniridia-Wilms Tumor Syndrome
Mentally retarded Growth retarded Blindness Tumors
on kidneys Short lifespan
14
Thirteen Q Deletion Syndrome
1 in 500,000 births 46 chromosomesXY or XX 13
Deletion of lower arm
15
Thirteen Q Deletion Syndrome
Mentally retarded Deformed face No
thumbs Heart disease Short lifespan
16
Prader-Willi Syndrome
1 in 5,000,000 births46 chromosomes XY97
XX3 15 Deletion of lower arm
17
Prader-Willi Syndrome
Small bird-like head Mentally retarded Respiratory
problems Obesity Short lifespan
18
Eighteen Q Deletion Syndrome
1 in 10,000,000 births 46 chromosomesXY or
XX 18 Deletion of lower arm
19
Eighteen Q Deletion Syndrome
Mentally retarded Heart disease Abnormal hands
and feet Large eyes Large ears Normal lifespan
20
Cat-Eye Syndrome
1 in 1,000,000 births 46 chromosomesXY or
XX 22 Deletion of bottom arm
21
Cat-Eye Syndrome
Fused fingers and toes Mentally retarded Small
jaw Heart problems Normal lifespan
22
Four-Ring Syndrome
1 in 10,000,000 births 46 chromosomesXY or
XX 4 Inversion
23
Four-Ring Syndrome
Cleft palate Club feet Testes dont descend Short
lifespan
24
Down Syndrome
Down Syndrome Trisomy
1 in 31,000 births46 chromosomes XY97
XX3 14/21 Translocation
1 in 1,250 births 47 chromosomesXY or XX 21
Trisomy Nondisjunction
25
Down Syndrome
Short, broad hands Stubby fingers Rough
skin Impotency in males Mentally retarded Small
round face Protruding tongue Short lifespan
26
Pataus Trisomy Syndrome
1 in 14,000 births 47 chromosomesXY or XX 13
Trisomy Nondisjunction
27
Pataus Trisomy Syndrome
Small head Small or missing eyes Heart
defects Extra fingers Abnormal genitalia Mentally
retarded Cleft palate Most die a few weeks
after birth
28
Edwards Trisomy Syndrome
1 in 4,400 births47 chromosomes XX80
XY20 18 Trisomy Nondisjunction
29
Edwards Trisomy Syndrome
Small head Mentally retarded Internal organ
abnormalities 90 die before 5 months of age
30
Jacobs Syndrome
1 in 1,800 births 47 chromosomesXYY only 23
Trisomy Nondisjunction
31
Jacobs Syndrome
?
Normal physicallyNormal mentally Increase in
testosterone Acne Normal lifespan
32
Kleinfelter Syndrome
1 in 1,100 births 47 chromosomesXXY only 23
Trisomy Nondisjunction
33
Kleinfelter Syndrome
Scarce beard Longer fingers and
arms Sterile Delicate skin Low mental
ability Normal lifespan
34
Triple X Syndrome
1 in 2,500 births 47 chromosomesXXX only 23
TrisomyNondisjunction
35
Triple X Syndrome
Normally physically Normal mentally Tall Fertile
normal lifespan
36
(No Transcript)
37
(No Transcript)