GENETIC DISEASES THAT ARE INHERITED

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GENETIC DISEASES THAT ARE INHERITED
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Genetic Mistakes come in two kinds

• 1. DNA mutations cause changes in a single gene
  
• Ex. Mutation in brown eye protein
  instructions causes it not to be made
  properlyend up with blue eyes.

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Genetic Mistakes come in two kinds

• 2. Chromosomal mistakes affect MANY genes
• Lets look at these first because there are fewer
  human examples

WHOLE THING IS MESSED UP!!!
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How to Identify ChromosomalAbnormalities in
unborn children???
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Types of Prenatal Diagnosis

• Amniocentesis- withdrawing a small amount of
  fluid/cells from the sac surrounding the fetus
  (16 weeks)
• Chorionic villus sampling (CVS)- cells from the
  tissue surrounding the fetus are removed and
  examined (8 weeks)

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Karyotype Photo Of Chromosomes

• Cells are grown in a culture dish
• Cell division is stopped in prophase (with
  chemicals)
• Cells are broken to release chromosomes
• Chromosomes are stained, photographed, and
  grouped

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Specially Stained Karyotype
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Grouped according to

• Size
• 2. Position of centromere
• 3. Banding pattern of
• the chromosome
• What gender does
• this karyotpye show?

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Nondisjuntion of chromosomes

• Nondisjunction means not separating properly
  during meiosis
• Gamete gets too few or too many chromosomes

WHOOPS!
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Turners Syndrome (monosomy X)What is wrong with
this karyotype?
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Turners Syndrome (monosomy X)

• 1 5,000 live births
• Only 45 Chromosomes in each cell
• Genetically female
• Sterile
• Short stature
• Normal intelligence
• (98 of these fetuses
• die before birth)

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What is wrong with this Karyotype?
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Downs Syndrome (Trisomy 21)

• Extra copy of chromosome 21
• 1 700 Children
• Altered phenotype moderately or severely
• Older women at higher risk for Downs child
• Heart defects
• Learning Disabilities
• Muscle weakness and prone to respiratory
  infections

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Edwards Syndrome (Trisomy 18)

• Almost every
• organ system affected
• 1 8,000 live births
• Generally do not
• live past first year
• Trisomy 18

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Edwards Syndrome (Trisomy 18) What is wrong
with this karyotype?
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Patau Syndrome (Trisomy 13) What is wrong with
this karyotype?

• Serious eye, brain,
• circulatory defects
• 1 5,000 live births
• Rarely live more than
• a few months

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Klinefelter Syndrome (XXY) What is wrong with
this karyotype?

• Males
• Sterile
• Normal intelligence
• XXY

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Jacobs Syndrome (XYY)What is wrong with this
karyotype?

• Taller than average
• Below normal intelligence
• aggressive personalities
• XYY

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Trisomy X What is wrong with this karyotype?

• Females
• 11000 live births
• Healthy and fertile
• Usually cannot be
• distinguished except
• by karyotype

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Cri Du Chat Syndrome

• is an abnormality resulting in the deletion of
  part of the short arm of chromosome 5.
• Sometimes this syndrome is called "Cat Cry
  Syndrome
• Learning Disabilities
• Physical impediments

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EXAMPLES OF SINGLE GENE MISTAKES

• DNA has a code of A,T,C, and G.
• If one single letter is changed, a mutation has
  occurred.
• This could be
• Good (blue eyes are a single mutation)
• Neutral (a freckle of skin or a mole are harmless
  changes)
• BAD! -even LETHAL

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EXAMPLES Cystic fibrosis

• A recessive mistakeinstructions for one protein
  in a membrane is shut down
• Causes dangerous build up of mucous in lungs and
  digestive system of human
• Human must be cf cf to have cystic fibrosis
• Human with CF cf is normal

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The blue people of Kentucky

• A recessive mutation in a blood protein which
  causes the blood to not be oxygenated as easily
  (blue color instead of pink or red)
• Humans appear very grey or bluish color in the
  skin/ nails and lips.
• Can be treated with a chemical to convert the
  protein to the correct configuration

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Huntingtons Syndrome

• A Dominant mutation H causing protein/enzyme
  malfunction
• One copy in your genes and you will get this
  disease
• In 20s, 30s or 40s, people with Huntingtons
  start to show symptoms of deterioration
• It affects all body systems until death
  occurs.there is no cure

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Hemophilia

• Sex-linked
• Recessive trait located on X chromosome
• Protein for normal blood clotting is disrupted
  and humans with this disease often bleed to death
  without regular medical treatment

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Sickle Cell Anemia

• Co-dominant Mutation in proteins of blood cells
• Normal blood cell is disc shaped
• Sickle cell is flattened and curved..gets stuck
  and causes swelling in blood vessels
• SC SC is normal adult
• SC sc has mild sickle cell and survives
• sc sc has severe sickle cell and will not
  surviveA LETHAL ALLELE!
• SC sc humans are more resistant to Malaria
  infection..hmmmmmm

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Human genome project

• Genome base sequence of all the DNA in an
• organism
• Project was started in 1988
• Was completed in 2005
• Map out every chromosome in the human body
• 24 chromosomes (1-22 plus the X and the Y)
• 30,000 to 60,000 genes made up of 3 billion
  pairs
• Only base pairs known.actual meaning of code is
  largely a mystery

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Assignment

• Find a single gene mutation disease
• Which gene is affected?
• What protein is affected?
• Is it dominant, recessive or some other
  inheritance?
• What are the symptoms of this disease?
• When do the symptoms start? (birth, later on
  etc)
• What is the prognosis (what will happen to the
  person)?
• What is the treatment?
• How common is it? OR how Rare?
• Any other interesting facts?
• 3 pages double spaced typed. Due next Wednesday.
• Cite three reliable sources (minimum!) NO wikis
  allowed