Transcript Genetic Disorders Power Point (Chapt. 9)

HUMAN GENETICS
Disorders
How information is taken
to detect genetic disorders
before birth
Blood test
Amniocentesis
Chorionic villus sampling CVS
Ultrasound imaging
Blood Test
Such as PKU –check if baby does not
have enzyme to break down PKU
Amniocentesis
small amount of amniotic fluid, which
contains fetal tissues, is sampled and the
fetal DNA is examined for genetic
abnormalities.
CVS
chorionic villus sampling
Sample of the placenta to test for genetic
abnormalities
Ultrasound imaging
visualizing internal body structures
including tendons, muscles, joints, vessels
and internal organs for possible pathology
or lesions
EX: good for
Achondroplasia
(short limbs)
AUTOSOMAL RECESSIVE
Autosomes = ,
chromosomes #1- #22
Cystic Fibrosis
Chromosome 7
FF = no CF
Ff = carrier
ff = has CF
(recessive)
Cystic Fibrosis-ff
It causes the
body to produce
a thick, sticky
mucus that
clogs the lungs
and digestive
tract.
Cystic Fibrosis (cont.)
Most common fatal genetic
disease in US today
Most common in Caucasians
Baby Skye CF treatment
CF Treatment Baby Video CF treatment –
young woman video (8:22)
Cystic Fibrosis Movie
PKU
Phenylketonuria (PKU)
Chromosome 12 -recessive
PKU on chromosome 12
Lacks the enzyme to break
down the amino acid
phenylalanine (found in milk)
PKU (cont.)
The breakdown
products can be
harmful to developing
nervous systems
Leads to mental
retardation.
Kate with PKU Movie
Julie
has
PKU;
been
treated
all her
KUVAN®
life
PKU
Chromosome 12
recessive
Put on low
protein diet
Avoid
phenylalanine
TAY SACHS
Highest rate in
Eastern
Results in
degeneration of European
Jews
the nervous
system.
Chromosome 15
recessive
Tay Sachs (cont)
 Lack enzyme to
break down fat,
accumulates in brain
 tt
 Chromosome 15
 Tay Sachs YouTube
 NOVA Online |
Cracking the Code of
Life | Watch the
Program Here #3
Tay-Sachs Symptoms
Symptoms first appear at 4 to 6 months
of age when an apparently healthy
baby gradually stops smiling, crawling
or turning over, loses its ability to
grasp or reach out, and eventually
becomes blind, paralyzed and unaware
of its surroundings. Death occurs by
age 4.
Albinism
Inability to
manufacture
pigments (melanin)
in skin and eyes
Autosomal
recessive trait
Chromosome 11
(will be in movie)
Albinism
Andy Warhol, a famous
musician and filmaker (now
dead), was an albino.
Rock musician
Edgar Winter, an
albino.
Different kinds of albinism
affect chromosomes 1, 9, 10,
11, 15 and X.
Often rapid back and forth eye
movement – lack of pigment in eyes.
Albinism Video (8:35)
AUTOSOMAL DOMINANT
Sickle Cell Anemia
Found in AfricanAutosomal
Americans
dominant
disease #11
Red blood cells
collapse and clot
blood vessels
Sickle-Cells
Normal Red
Blood Cells-like
a donut
Sickle-cells
collapse, hard,
clog vessels
Sickle-Cell Anemia
Codominant
SS = disease
AS = carrier (somewhat resistant to
malaria)
AA =normal hemoglobin
Sickle Cell Disease - What Causes
Sickle Cell Disease Video About.com
Pleiotropy
Alleles responsible for multiple symptoms
EX: sickle-cell anemia – low oxygen in
blood, resistance to malaria, spleen
damage, joint problems
Plasmodium in blood
Sickle-Cell Complications
1.pain episodes
2.strokes
3.increased infections
4.leg ulcers
5.bone damage
6.yellow eyes or jaundice
7.early gallstones
8.lung blockage
9.kidney damage and loss of body water in urine
10.painful erections in men (priapism)
11.blood blockage in the spleen or liver (sequestration)
12.eye damage
13.low red blood cell counts (anemia)
14.delayed growth
Huntington’s Disease
Woody Guthrie’s
disease (folksinger
1960’s)
Autosomal dominant
Does not manifest
itself until age 20’s 30’s
H=dominant disease
Familial (genetic)
Hypercholesterolemia
Autosomal dominant-H
Excess cholesterol in the blood
Chromosome 19
Most common is mutation in LDLR
low-density lipoprotein receptor
(bad cholesterol) FH YouTube (good) 1:53
Hypercholesterolemiapolygenic
Blood disease
Fatty patches
Polygenic hypercholesterolemia
(mutations on multiple genes)
FH (Familial
hypercholesterolemia)
Huntington’s
Chromosome 4
Autosomal dominant
Atrophy of brain
Uncontrollable
muscle spasms

Huntington's Disease Information - HOPES - HOPES Video
Player (SWF)
 (segment 4)

New Treatment for Huntington's Disease - Health Videos – redOrbit
40+ CAG’s

HowStuffWorks Videos "Treating
Huntington's Disease"
Huntington’s
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Clumsiness
Jaw clenching
Loss of coordination and balance
Slurred speech
Swallowing and/or eating difficulty
Uncontrolled continual muscular contractions
Walking difficulty, stumbling
Hostility/irritability
Inability to take pleasure in life
Lack of energy
person with Huntington's also may exhibit psychotic behavior:
Delusion
Halluciations
Inappropriate behavior (e.g., unprovoked aggression)
Paranoia
Achondroplasia
-Autosomal
Dominant
-chromosome 4
Achondroplasia
Dwarfism
Average adult male
height of 52 inches;
average adult female
height of 49 inches
short stature
Dwarfism
shortening of limbs,
trident hands
prominent forehead,
Achondroplasia
FAQ
Can short-statured
couples become the
parents of averagesize children?
AA=dead
Aa=Achondroplasia
aa=normal
A
A
a
a
FAQ
Can short-statured
couples become the
parents of average-size
children?
AA=dead
Aa=Achondroplasia
aa=normal
A
a
A AA
Aa
Aa
aa
a
Familial (genetic)
Alzheimer syndrome
Widespread
nerve cell
dysfunction and
cell death,
neurotransmitter
deficiencies
Dementia
Alzheimer Syndrome
Autosomal Dominant
Found on
Chromosome 1, or
10, or 14, or 19, or 21
APO4, is a cholesterolcarrying protein linked
to development a
protein that forms
plaque in the brain
Brain Loss
Alzheimers Disease -3D animation You Tube (1 min)
Inside the Brain: Unraveling the Mystery of
Alzheimer's Disease [HQ] (4:22)
Early or mild stage:
What is Alzheimer's? YouTube (3:15)
 memory loss, especially of recent events
 difficulty in recalling names and conversations
 misplacing objects
 becoming lost in familiar neighborhoods
 repeating stories and conversations
 difficulty in learning new information
 personality changes
 decreased motivation and drive
 easily upset or anxious
Marfan Syndrome
autosomal
dominant
disorder
 chromosome 15
(will be in movie)
Marfan’s: taller, pigeon
chest
Spidery fingers, enlargement of aorta
Marfan Syndrome
Marfan Syndrome You Tube (2:45)
a connective tissue
disorder,
Affects skeleton,
lungs, eyes, heart
and blood vessels.
unusually long
limbs
affected Abraham
Lincoln.
SEX-LINKED DISORDERS
On X
chromosome
Hemophilia- “bleeder’s disease”
X-linked recessive
Hemophilia passed by
queen victoria
Blood does not Czar Nicholas
clot normally
royal family
Sex-linked
recessive
Missing AHF
(clotting
factor in blood)
Royal PedigreeHemophilia
“bleeder’s disease”
XHXh = female
carrier
XhXh = female
hemo
 Hemophilia Video
(from WHF)
 Young Boy
hemophilia treatment
You Tube
XHY = normal
male
XhY = hemo male
Color Blindness
inability to perceive differences
between some of the colors that
others can distinguish.
More common in males
Sex-linked (red and
Green) on
X chromosome
recessive
Color Blindness
3 seconds to
determine number
Ishihara Test for Color
Blindness
The individual with
normal color vision
will see a 5 revealed
in the dot pattern.
An individual with
Red/Green (the
most common) color
blindness will see a
2 revealed in the
dots.
Ishihara
Test for
Color
Blindness
Color blindness=can’t tell
certain colors
Recessive on X
chromosome = c
XCXc = normal
female (carrier)
XcY = color-blind
male
What numbers do you see?
Note: X and Y used
Need X and Y on Punnetts
Duchenne Muscular
Dystrophy
DMD
GuillaumeBenjamin
Duchenne de
Boulogne
Duchenne Muscular Dystrophy
On Xm chromosome
Weakens and degenerates
muscles
Found mostly in males
#1 fatal disease to affect boys
DMD
absence of dystrophin, a protein that
helps keep muscle cells intact
Leg muscles
first. Calves
often
enlarged.
DMD
Onset ·Early childhood about 2 to 6 years.
 Symptoms ·
Generalized
weakness of muscle
Wasting affecting
limb and trunk
DMD Timeline YouTube
(good one) (5:43)
DMD
Survival rare
beyond late
twenties.
X-linked
recessive
(females are
carriers).
POLYGENIC DISORDERS
Determination of
disorder occurs on
more than one
chromosome
SPINA BIFIDA
is a fault in the spinal
column in which one or
more vertebrae (the bones which
form the backbone) fail to form
properly, leaving a gap or split.
Spina Bifida (POLYGENIC)
#6, #14 and others
Gap in spinal
column
 Spinal Bifida Genetics
You Tube (1:53)
Shunts often put in the brain
to drain the fluid
Spinal Bifida Facts Video You Tube (4:38)
Agent Orange
 Children with Spina
Bifida whose parent was
in contact with Agent
Orange during the
Vietnam War are
compensated
Cleft Lip/Cleft Palate
#11, #17, #22
A cleft is an
opening in the lip,
the roof of the
mouth (hard
palate) or the soft
tissue in the back
of the mouth (soft
palate).
Clefts
Clefts occur more often among Asians and
certain groups of American Indians
than among whites.
They occur less frequently
among blacks.
Cleft lip/palate
As you can imagine
there are feeding
problems
#11, #22, #17 –
Polygenic
 Cleft Lip and Palate You Tube (5;04)
On Y chromosome
Testes
determining
factor
SRY gene
A sex-determining gene on the Y
chromosome
(Sex-determining region Y)
NOTE:
If you are born with no “X”
chromosome- it is fatal
If missing an autosome-it is
fatal
X chromosome
Sex-linked traits
Triple-X Syndrome
triplo-X
trisomy X
XXX syndrome
47,XXX aneuploidy
There is usually no distinguishable
difference to the naked eye
between women with triple X
and the rest of the female population.
Triple-X Syndrome
Although females with this condition may
be taller than average, this chromosomal
change typically causes no unusual
physical features.
Most females with triple X syndrome have
normal sexual development and are able
to conceive children.
Nondisjunction
Chromosomes
to segregate
unevenly
during meiosis
Mistakes in
Meiosis
Down’s Syndrome
Trisomy 21
Extra fold over
eye
Sluggish
muscles
Mental
problems
Trisomy 21 Karyotype
Nondisjunction
Turner’s Syndrome
Adults with Turner syndrome are short,
averaging around four feet, eight inches in
height.
Flap in neck
Small breasts
But girls with Turner syndrome
don't start life as very short
individuals - they become short
over time-do not develop
sexually
Turner’s Syndrome 45 X0
Kleinfelter’s 47 XXY
Kleinfelter’s
-Testes are small
-breast growth (gynaecomastia)
-poorly developed secondary sexual
characteristics.
Klinefelter’s
Men are sterile (no sperm).
Special Topics In Human
Genetics
BARR BODIES
When a female is
born one of her X
chromosomes is
inactivated = a
Barr Body (early
in embryonic
development)
Used to test
femaledness at
Olympics
So there is not
excess of X info
in females
Calico Cat – X linked
Only females
have 3 colors
(orange,
black, white)
Looks like
“Pepper”
Multiple colors in cats mostly
in females
GENETIC DISORDERS REFERENCE
SHEET:
Down Syndrome (Trisomy 21)
Edward's Syndrome (Trisomy 18)
Patau Syndrome (Trisomy 13)
Klinefelter Syndrome (47, XXY)
Turner Syndrome (45 XO)
Metafemale (46XXX)-taller
Autosomes (#1-22) so 44 if normal